Download 1775-6.5.5, PLC-3 Family I/O Scanner Comunication

PLC3 Family I/O Scanner
CommunicationAdapter Module
User Manual
Important User Information
Because of the variety of uses for this product and because of the differences
between solid state products and electromechanical products, those responsible
for applying and using this product must satisfy themselves as to the
acceptability of each application and use of this product. For more information,
refer to publication SGI-1.1 (Safety Guidelines For The Application,
Installation and Maintenance of Solid State Control).
The illustrations, charts, and layout examples shown in this manual are intended
solely to illustrate the text of this manual. Because of the many variables and
requirements associated with any particular installation, Allen-Bradley
Company cannot assume responsibility or liability for actual use based upon the
illustrative uses and applications.
No patent liability is assumed by Allen-Bradley Company with respect to use of
information, circuits, equipment or software described in this text.
Reproduction of the contents of this manual, in whole or in part, without written
permission of the Allen-Bradley Company is prohibited.
Throughout this manual we make notes to alert you to possible injury to people
or damage to equipment under specific circumstances.
ATTENTION: Identifies information about practices or
circumstances that can lead to personal injury or death, property
damage or economic loss.
Attention helps you:
- Identify a hazard
- Avoid the hazard
- recognize the consequences
Important: Identifies information that is critical for successful application and
understanding of the product.
Summary of Changes
Summary of Changes
Additional Information
In general, we improved the format and added greater detail to this manual.
We have also corrected incorrect and confusing concepts throughout the
manual.
The following table lists specific changes we made since:
We have:
Added details concerning 230.4 kbps support
To chapter/Appendix:
2
Updated LIST configuration capabilities and displays
- added the new feature: DH+ Active Nodes to Status File 6
Included the recommended numbers for assigning to slaves and
masters in a PeertoPeer configuration link
Added extensive text concerning DH addressing on:
• PLC2 logical data
• PLC3 logical binary
• Logical ASCII
• data type
• word range
• Additional examples of each type of addressing
5
Added the feature of identifying remote stations in an assignment
command with a symbol
Added a new chapter: Diagnostic Methods
7
Expanded Binary Command Language
A
Table of Contents
Summary of Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11
Additional Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11
Using this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
P 1
Manual Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
What this Manual Contains . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vocabulary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
P 1
P 1
P 2
P 2
Scanner Hardware and Installation . . . . . . . . . . . . . . . . . .
11
Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Scanner Features and Functions . . . . . . . . . . . . . . . . . . . . . . . . .
Hardware Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuring the Scanner Hardware . . . . . . . . . . . . . . . . . . . . . . .
Connecting to a Backup System . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting to a DH or DH+ Network . . . . . . . . . . . . . . . . . . . . . .
Connecting to the I/O Channel Terminal Arm . . . . . . . . . . . . . . . . .
11
11
13
16
112
113
116
Configuring the Scanner through LIST . . . . . . . . . . . . . . . .
21
Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accessing the LIST Function . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuring the Communication Channels . . . . . . . . . . . . . . . . . .
Setting the Rack Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuring the Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21
21
23
220
220
I/O Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Effect of I/O Scan on Program Execution . . . . . . . . . . . . . . . . . . .
PeertoPeer and Backup Communication . . . . . . . . . . . . . . . . . .
31
31
33
DH and DH+ Communication . . . . . . . . . . . . . . . . . . . . . . .
41
Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Communication Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Solicited and Unsolicited Messages . . . . . . . . . . . . . . . . . . . . . . .
Levels of Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Data Transfers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Choosing Between DH or DH+ Communication . . . . . . . . . . . . . . .
Operating Backup Configurations on a DH or DH+ Link . . . . . . . . .
Operating Multiple Links in One System . . . . . . . . . . . . . . . . . . . .
41
41
44
44
45
48
412
414
414
ii
Table of Contents
Addressing DH and DH+ Data Transfers . . . . . . . . . . . . . .
51
Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Addressing Field Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interpreting Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Addressing Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifying Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using PLC2 Logical Data Addressing . . . . . . . . . . . . . . . . . . . . .
Using PLC3 Logical Binary Addressing . . . . . . . . . . . . . . . . . . . .
Using Logical ASCII Addressing . . . . . . . . . . . . . . . . . . . . . . . . .
Addressing Stations on a Local Link . . . . . . . . . . . . . . . . . . . . . .
Addressing Stations on a Remote Link . . . . . . . . . . . . . . . . . . . . .
Assignment Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Programming Examples of Assignment Commands . . . . . . . . . . .
51
51
51
52
52
53
55
58
510
511
512
515
Programming DH and DH+ Message Procedures . . . . . . . .
61
Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Message Instruction Considerations . . . . . . . . . . . . . . . . . . . . . .
Editing the Message Instruction . . . . . . . . . . . . . . . . . . . . . . . . . .
Editing Message Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using User Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using System Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Message Procedure Commands . . . . . . . . . . . . . . . . . . . . . . . . .
CREATE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DELETE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Execute Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EXIT Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GOTO Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IF Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ON_ERROR Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
STOP Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adding Comments to Your Message Procedure . . . . . . . . . . . . . .
Programming Examples for a Message Procedure . . . . . . . . . . . .
61
61
62
64
64
66
66
67
613
614
614
615
615
615
616
616
617
617
619
619
Diagnostics Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
71
Chapter Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DH/DH+ Message Procedure Diagnostics . . . . . . . . . . . . . . . . . .
Diagnosing Faults with Module Status Indicators . . . . . . . . . . . . . .
Remote I/O Adapter Faults (Status File 2) . . . . . . . . . . . . . . . . . . .
I/O Communication Retry Counts (Status File 3) . . . . . . . . . . . . . .
Retries for a PeertoPeer or Backup Communication Channel . . . .
DH/DH+ Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
71
71
76
77
78
79
710
Table of Contents
iii
DH/DH+ Diagnostic Assignment Command . . . . . . . . . . . . . . . . .
711
Binary Command Language . . . . . . . . . . . . . . . . . . . . . . .
A1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Extended Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A1
A1
A14
A16
DH/DH+ Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Local Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reply Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Remote Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B1
B1
B1
B2
DH and DH+ Command Set . . . . . . . . . . . . . . . . . . . . . . . .
C1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C1
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D1
Preface
Using this Manual
Manual Objectives
What this Manual Contains
This preface tells you how to use this manual properly and efficiently for
the tasks you have to perform. Read this chapter before you program a
PLC-3 family programmable controller.
Chapter/
Appendix
Title
What's Covered
1
Using this Manual
Manual's purpose, audience, and contents
2
Scanner Hardware
and Installation
Hardware components and procedures for installing a
scanner
3
Configuring the
Using the LIST function to configure the scanner
Scanner Through LIST
4
I/O Communication
Timing and programming considerations when using
the scanner for I/O communication
5
DH and DH+
Communication
Concepts, programming, and timing considerations
6
Addressing DH and
DH+ Data Transfers
Specifying data addresses in message commands that
communicate over a DH or DH+
7
Programming DH and
DH+ Message
Procedures
Operating the message instruction to communicate
over a DH or DH+
8
Diagnostic Methods
Techniques and indicators for monitoring scanner status
A
Binary Command
Language
Commands used by an external control device to
communicate with a PLC3 family controller through
channel 0 of the front panel
B
DH/DH+ Error Codes
DH and DH+ error codes and meanings
C
DH and DH+
Command Set
DH and DH+ commands supported by the scanner
D
Specifications
Scanner operating and environmental specifications
P- 1
Preface
Audience
In this manual, we assume that you know how to program and operate an
Allen-Bradley PLC-3 or PLC-3/10 programmable controller system. If
you are not familiar with these controllers, refer to the following
publications:
Publication
Vocabulary
P- 2
Title
17706.2.2
Data Highway Cable and Data Highway Plus Installation Manual
17706.5.15
PLC3 Industrial Terminal (cat. no. 1770T4) User's Manual
17706.5.16
Data Highway/Data Highway Plus Protocol Command Set User's Manual
17716.5.83
Remote I/O Adapter Module (cat. no. 1771ASB) User's Manual
17756.3.1
PLC3 Backup Concepts Manual
17756.4.1
PLC3 Family Programming Manual
17756.7.1
PLC3 Family Installation and Operation Manual
17846.5.1
Industrial Terminal (cat. no. 1784T50) User's Manual
62006.5.3
PLC3 Programming Software User's Manual
We refer to certain types of equipment and terms throughout this manual.
To make the manual easier for you to read and understand, we avoid
repeating full product names where possible.
We refer to the:
As the:
I/O ScannerCommunication Adapter Module
(cat. no. 1775S5, SR5)
scanner
PLC3 or PLC3/10 programmable controller system
controller or the system
ladderdiagram or user program that controls
PLC3 processor operation
ladder program
Data Highway link
DH link
Data Highway Plus link
DH+ link
Industrial terminal system, e.g., AllenBradley 1784T4, T47,
T53, or 6160T60 terminals, or an computer with 6200 software
programming terminal
Preface
In addition, you may encounter words in different typefaces. We use these
conventions to help differentiate descriptive information from information
that you enter while programming your scanner.
The Return key looks like this (boldface and in brackets):
[Return]
Words or commands that you enter appear in boldface. For example:
$047
$FILE_A
Variables that you enter appear in italics. For example:
Type link:node and press [Return]
Messages or prompts on the screen look like this:
ENTER STATION AND INPUT FILE #>
“Type” means –– type in the information
“Enter” means –– type in the information and then press the [Return]
key.
P- 3
Chapter
1
Scanner Hardware and Installation
Chapter Objectives
This chapter describes:
the features and functions of the 1775-S5, -SR5 scanners
the hardware components on the scanner
how to install the scanner
how to connect and configure the scanner to a(n):
- backup system
- Data Highway (DH) or Data Highway Plus (DH+)
communication network
- I/O adapter for I/O scanning
- programming terminal
- scanner in another PLC-3 or PLC-3/10 chassis
Scanner Features and
Functions
The 1775-S5, -SR5 scanner has four communication channels to
communicate with any of the following:
I/O adapters (cat. no. 1771-AS, -ASB)
node adapter devices
a scanner in a backup PLC-3 or PLC-3/10 processor
PLC-5 products in adapter mode
up to six PLC-3 or PLC-3/10 processors
On channel 4, you can communicate with these additional devices:
up to 64 stations on a DH or DH+ link
a programming terminal
In the following chapters, we describe how to configure and operate these
channels. Table 1.A summarizes the operating features and functions.
1-1
Chapter 1
Scanner Hardware and Installation
Table 1.A
1775S5, SR5 Scanner Features and Functions
Features
1-2
Functions
Four I/O communication
channels
Communicate with I/O adapter modules in an I/O chassis. You
can connect up to 32 I/O chassis to one I/O channel. The
scanner can communicate with up to 4,096 I/O.
I/O scan priority
Scan the I/O chassis according to a sequence that you select.
DH/DH+ channel
Communicate with other AllenBradley controllers and/or
computers on a DH or a DH+ channel. Also provides direct
connection for a programming device.
Status indicators
Keeps you informed on the scanner's status including:
• forces in the system
• DH/DH+ channel
• I/O communication channels
Thumbwheel switch
Distinguishes one scanner from another. You can have up to:
• 15 scanners in a PLC3 system (S5 scanner)
• 2 scanners in a PLC3/10 system (SR5 scanner)
Backup connector
Transfers control to a backup PLC3 or PLC3/10 system if a
fault shuts down the primary system.
Terminal arm
Makes connections to:
• 1771 I/O chassis up to 10,000 cable feet away from the
scanner via twinaxial cable (cat. no. 1770CD) for I/O
communication
• Communication channels on scanners in up to six separate
PLC3 or PLC3/10 systems via twinaxial cable for
peertopeer communication
• Communication channel on a scanner in a backup PLC3 or
PLC3/10 system via twinaxial cable for backup
communication
Message procedure
commands
Easy to use commands that you can use to transfer data over
a DH or DH+ link and combine in procedures for:
• complex logic decisions, looping, and nesting
• symbolic representation of data and addresses
• embedded arithmetic expressions and logic operations
• error checking and reporting
• decimal, octal, or binarycodeddecimal data entry
• functions for converting data values to and from BCD
Chapter 1
Scanner Hardware and Installation
Hardware Features
Figure 1.1 shows the hardware components on your scanner.
Figure 1.1
Hardware Features on the Scanner
1775S5 Scanner
1775SR5 Scanner
PASS and FAIL indicators
Thumbwheel switch
Forces enabled indicator
I/O channel status indicators
DH/DH+ status indicators
Backup connector
DH/DH+ connectors
I/O channel terminal arm
The scanner also has switch settings located on the top
and bottom edges.
15274
1-3
Chapter 1
Scanner Hardware and Installation
Pass and Fail Indicators
The indicators labeled PASS and FAIL (Figure 1.2) keep you informed
about the general condition of the scanner:
PASS (green)
FAIL (red)
Meaning
on
off
normal operation
off
on
module fault
on
on
powerup or system reset
off
off
system is not on or module has lost power
Forces Enabled Indicator
The yellow indicator labeled FORCE (Figure 1.2) illuminates when I/O
forcing is enabled in the system.
I/O Channel Status Indicators
The four green indicators labeled CH1, CH2, CH3, and CH4 (Figure 1.2)
correspond to one of the four I/O channels.
Indicator
Status
CHx
ON
Configured for
I/O scanning
FLASHING
There is a fault on one or more of the I/O chassis on the
corresponding I/O channel.
OFF
No I/O chassis are configured on the corresponding I/O
channel or the channel is inactive.
CHx
ON
The channel is functioning properly.
Configured for
peertopeer
communication
FLASHING
CHx
Configured for
backup
communication
Communication between scanner module and the I/O chassis
on the corresponding I/O channel is properly established.
The input file is too small at the processor receiving data. The
slave or master does not exist. Communication retry.
OFF
The channel is inactive.
ON
The channel is functioning properly.
FLASHING
OFF
1-4
Description
The input file is too small at the processor receiving data. The
partner is not responding.
The channel is inactive.
Chapter 1
Scanner Hardware and Installation
DH/DH+ Status Indicators
The five indicators labeled XMTG, RCVG, RDY, ERR, and DIS
(Figure 1.2) show you the status of the DH or DH+ channel.
Indicator
Color
When this led is on, (the scanner is)
XMTG
green
transmitting a message.
RCVG
green
receiving a message.
RDY
green
ready to transmit a message.
ERR
red
DIS
yellow
programming or communication error detected.
DH/DH+ connectors are disabled or duplicate
DH+ station address if blinking.
When the scanner is polling, both the XMTG and RCVG LEDs turn on.
Figure 1.2
Indicator Locations for 1775S5 and 1775SR5 Scanner Modules
1775SR5
Scanner
1775S5
Scanner
Thumbwheel switch
1-5
Chapter 1
Scanner Hardware and Installation
Configuring the Scanner
Hardware
Before you install the scanner, you need to configure the module. You use
the connectors, terminal arm, and switches when:
setting the thumbwheel and switches
installing the scanner
We describe these connections and configurations in the
following sections.
Setting the Thumbwheel and Switches
Before inserting the scanner into a chassis:
1.
Set the thumbwheel switch to a unique number (1 to 15) to enable the
processor to distinguish one scanner from another. You must have a
scanner with the thumbwheel set for 1.
2.
Make the necessary switch settings.
Figure 1.3 shows the location of the backup switches for the 1775-S5 and
1775-SR5 scanner moduels.
Figure 1.3
Location of Backup Switches for 1775S5 and SR5 Scanner Modules
Backup switch at
bottom edge of module
Terminator switch at
bottom edge of module
18754
Setting a Terminator on a Communication Channel
On the bottom edge near the front of the scanner is a set of four switches.
With these switches, you can connect a terminator across the line when the
scanner is an end device on a DH, DH+, I/O, peer-to-peer, or backup
communication link (Figure 1.4) on the corresponding channel.
Important
: When using internal terminators, removing the terminal swing
arm from the scanner causes the communication channels to be
unterminated. You may want to leave the switch up and install the optional
1770-XT external 150 ohm terminator.
1-6
Chapter 1
Scanner Hardware and Installation
When a channel is configured for a communication rate of 230.4 kbps, the
corresponding terminator switch must be up away from the board. An
external 82 ohm terminator must be used in this configuration.
Figure 1.4
Setting a Terminator on a Communication Channel
Up (away from board)
1
2
3
Down (toward board)
4
When DOWN, a 150 ohm terminator is connected on
the corresponding communication channel.
15422
Setting the Protocol, Communication Rate, and Station Address for
Channel Four
On the top edge near the rear of the scanner are two sets of switches. You
can use these two sets of switches to set the protocol, communication rate,
and station address (Figure 1.5 and Figure 1.6).
You can set the protocol for:
DH link
DH+ link
I/O link
or LIST configurable (selections in the LIST set the protocol)
If you set the protocol switches for:
Then you must specify the station address by:
DH or DH+
setting the set of eight switches next to the protocol
and communication rate switches.
list configurable
using the station number selection in LIST. For
more information, see chapter 2.
You can set the communication rate to the following:
Select:
For:
57.6 kbps
I/O, peertopeer, backup, DH, or DH+ communication
115.2 kbps
I/O, peertopeer, backup, or DH+ communication only
230.4 kbps
I/O, peertopeer, or backup communications
1-7
Chapter 1
Scanner Hardware and Installation
Not all DH+ stations are capable of operating above 57.6 kbps. You must
reference the appropriate users manual for the maximum communication
rate for each device.
ATTENTION: Channel 4 may not be configured for DH or
DH+ when operating any of the other communication channels
at 230.4 kbps. Otherwise, I/O rack retries and missing inputs in
a listen only mode backup system may result.
Figure 1.5
Setting the Protocol, Communication Rate, and Station Address for
Channel Four
Up (away from board)
1
Communication
Rate (bps)
57.6k
115.2k
230.4k
2
3
Down (toward board)
4
Switch
1
2
down
up
down
down
down
up
Protocol
DH
DH+
I/O scan
Configurable
through LIST
Switch
3
4
down
up
down
up
down
down
up
up
If you set the protocol switches for DH or DH+ communication, you must
set the station number (Figure 1.6). Valid station numbers range from 000
to 376 octal for DH and 00 to 77 octal for DH+.
Switch numbers:
correspond to the:
7 and 8
first digit (MSD)1
4, 5 and 6
second digit
1, 2 and 3
third digit (LSD)2
1 MSD = Most Significant Digit
2 LSD = Least Significant Digit
1-8
Chapter 1
Scanner Hardware and Installation
Figure 1.6
Setting the Station Number for the DH or DH+ Channel
If you are using channel 4 for DH or
DH+ communication, then set the
station number with these switches.
Up (away from board)
1
2
3
4
5
6
Down (toward board)
7 8
Digit
1
2
3
Digit
4
5
6
Digit
7
8
0
1
2
3
4
5
6
7
down
up
down
up
down
up
down
up
down
down
up
up
down
down
up
up
down
down
down
down
up
up
up
up
0
1
2
3
4
5
6
7
down
up
down
up
down
up
down
up
down
down
up
up
down
down
up
up
down
down
down
down
up
up
up
up
0
1
2
3
down
up
down
up
down
down
up
up
(Most Significant)
(Least Significant)
Example:
The switch settings for station number 037 are:
1
2
3
4
5
6
7
8
up
up
up
up
up
down
down
down
7
Station number
3
0
037
1-9
Chapter 1
Scanner Hardware and Installation
Setting Backup System Functions
On the bottom edge (Figure 1.7) near the rear of the scanner is a set of 4
switches. If you are using a backup configuration, then you can set
switches 2 and 3 to define the switchover type. For detailed information
on backup, refer to the PLC-3 Backup Concepts Manual (publication
1775-6.3.1).
Figure 1.7
Setting Backup System Functions
Always Up
Up (away from board)
1
2
3
Down (toward board)
4
If you are operating a backup system,
then set these switches to set up the
type of switchover.
Switchover Type
1
Switch
2
3
System
(primary
or backup)
Auto with controllable
switchback
down
up
both
Auto with no switchback
down
up
up
up
primary
backup
Manual
up
down
both
If you are not operating a backup system, then set switches 2 and 3 to the UP position.
The backup switches for scanners other than thumbwheel number 1 should
be set away from the board.
Installing the Scanner
After you configure the scanner, insert the scanner into any slot of a:
PLC-3 processor chassis (cat. no. 1775-A1, -A2)
PLC-3/10 processor chassis (cat. no. 1775-A3)
PLC-3 and PLC-3/10 CPUs, scanners, and memories are not
interchangeable.
1-10
Chapter 1
Scanner Hardware and Installation
The chassis electromechanically interlocks helping to guard against
inserting or removing modules while power is on.
ATTENTION: Do not change the thumbwheel setting on a
scanner while power is on. This could result in equipment
damage.
PLC-3 and PLC-3/10 systems require a scanner with the thumbwheel set
to 1. If you are using a multi-chassis system, the scanner set to 1 must be
in the chassis with the front panel.
You can operate a 1775-S5 scanner with a 1775-S4A, -S4B scanner in a
PLC-3 system and a 1775-SR5 with a 1775-SR scanner in a PLC-3/10
system. However, note the following cautions.
ATTENTION: You can replace a 1775-S4A, -SR scanner with
a 1775-S5, -SR5 scanner, however, you must:
perform a logical save of memory without saving the module
status area (E2)
clear memory after replacing one scanner with another.
restore the previously stored memory
configure each 1775-S5, -SR5 scanner communication
channel in LIST.
Failure to observe this caution could result in equipment
damage and/or undesired machine operation.
1-11
Chapter 1
Scanner Hardware and Installation
Connecting to a Backup
System
With a backup system, if a major fault occurs, the primary system shuts
down and the backup system takes over the outputs to enable your process
to continue. To set up a backup system, connect a backup cable (cat. no.
1775-CBA, -CBB) from the 6-pin connector labeled BACK UP on scanner
number 1 in a primary system to the backup connector on scanner number
1 in a backup system (see Figure 1.8).
Figure 1.8
Connecting the Scanner to a Backup System
Primary System
Backup System
Backup Cable
(cat. no. 1775CBA,
-CBB)
15406
ATTENTION: When using a backup system:
Do not backup a 1775-S5, -SR5 scanner with a 1775-S4A,
-S4B, or -SR scanner.
If you are using manual switchover and switchover occurs,
you must wait at least 60 seconds before switching back to
the primary system.
Failure to observe these cautions could result in equipment
damage and/or unpredictable machine operation.
For detailed information on installing and operating a backup system, refer
to the PLC-3 Backup Concepts Manual (publication 1775-6.3.1).
1-12
Chapter 1
Scanner Hardware and Installation
Connecting to a DH or DH+
Network
The scanner enables the connectors labeled DH/DH+ when you set
communication channel 4 for a DH or DH+ link. You can use the:
9-pin connector to connect the programming terminal for programming
the processor on a DH+ network
3-pin connector to connect the controller to a DH or DH+ netwrok
Programming Terminal Connections
The 9-pin connector provides direct connection via the Industrial Terminal
Processor Cable.
Cable
Communication Board
1784CP5
1784KTK1
1784CP
1784KT
For detailed information on installing and operating the Industrial Terminal
(cat. no. 1784-T50) with the controller, refer to the Industrial Terminal T53
User’s Manual (publication 1784-6.5.1).
DH/DH+ Connections
The 3-pin connector provides direct connection via Twinaxial Cable (cat.
no. 1770-CD) to a DH or DH+ link (Figure 1.9). For detailed information
on installing a DH or DH+, refer to DH Cable Assembly and Installation
Manual (publication 1770-6.2.2).
1-13
Chapter 1
Scanner Hardware and Installation
Figure 1.9
Example of DH and DH+ Configurations
Data Highway (DH) Link
PLC5
Family Controller
Computer
1775S5
Scanner
1785KA
Module
PLC3
Controller
1770KF2
KF2 Series B
Module
1770KF2
KF2 Series B
Module
DH
Link
PLC3 or
PLC3/10
Controller
Advisor 2+
Color
Graphic
System
PLC3/10
Controller
1775SR5
Scanner
1775KA
Module
Data Highway Plus (DH+) Link
PLC5
Family
Controller
Computer
1775S5
Scanner
PLC3
Controller
1770KF2
Series B
Module
DH +
Link
1770KF2
Series B
Module
Advisor 2+
Color
Graphic
System
1-14
PLC3/10
Controller
1784T50
Terminal
1775SR5
Scanner
15272
Chapter 1
Scanner Hardware and Installation
To make connections to the scanner, connect the 1770-CD cable to the
screw terminals on the 3-pin connector (Figure 1.10).
Figure 1.10
Connecting the Scanner to a DH or DH+
Terminals on
the scanner
Connecting the
scanner to another
scanner on a DH or
DH+ link
1
Clear
Clear
1
SH
Shield
Shield
Blue
Blue
SH
2
2
Clear
8
SH
Shield
Shield
Blue
Blue
Connecting the
scanner to a
computer via a Series
B 1770KF2 module
on a DH or DH+ link.
1
Clear
Clear
SH
Shield
Shield
Blue
Blue
9 10 11 12 13 14 15
7
6
5
3 4
1 2
2
8
1 2
3 4
5
2
9 10 11 12 13 14 15
Clear
6
1
Connecting the
scanner to a
computer via a
computer interface
module on a DH link.
7
Twinaxial Cable
(cat. no. 1770CD)
15Pin Connector
on a Communication
Interface Module
15Pin Connector
on a Communication
Interface Module
(cat. no. 1770KF2,
series B)
15408
The scanner has an on-board switch-selectable terminator. If the scanner is
an end device in the DH or DH+ link, set the terminator switch
corresponding to I/O channel 4 (see “Setting the Thumbwheel and
Switches,” page 1-6).
1-15
Chapter 1
Scanner Hardware and Installation
Connecting to the I/O
Channel Terminal Arm
The terminal arm provides connections for four I/O communication
channels (Figure 1.11). Functions of these channels include:
I/O communication
backup communication
peer-to-peer communication
If you select:
Then the maximum I/O channel cable length can be:
57.6 kbps
10,000 feet
115.2 kbps
5,000 feet
230.4 kbps
2,000 feet
Important: If you set the protocol for channel four to a DH or DH+ link,
the scanner automatically disables the channel four terminals, and enables
the DH/DH+ connectors (see “Connecting to a DH or DH+ Network,”
page 1-13).
Figure 1.11
I/O Channel Terminal Arm Connections
I/O
Channel 3
Line 1
Line 1
Shield
Shield
Line 2
Line 2
Line 1
I/O
Channel 1
I/O
Channel 4
Blue
Line 1
Shield
Shield
Line 2
Line 2
I/O
Channel 2
Clear
Twinaxial Cable
(cat. no. 1770CD)
1770XT
Terminator
(optional)
Connects to a Remote I/O Device for I/O communication or a scanner
in another PLC3 or PLC3/10 chassis for peertopeer or backup communication.
If the scanner is at the end of the channel, set the terminator switch corresponding
to the channel number. If the channel is configured for I/O at 230.4 kbps, disable
the terminator for the channel and install an external 82 ohm terminator
1-16
15409
Chapter 1
Scanner Hardware and Installation
Electrostatic Discharge
ATTENTION: Electrostatic discharge can degrade
performance or damage the module.
Electrostatic discharge can damage integrated circuits or semiconductors in
the scanner if you touch backplane connector pins. It can also damage the
scanner when you set configuration plugs and/or switches inside the
module. Avoid electrostatic damage by observing the following
precautions:
Touch a grounded object to rid yourself of charge before handling the
module.
Do not touch the backplane connector or connector pins.
When not in use, keep the module in its static shield bag.
1-17
Chapter
2
Configuring the Scanner through LIST
Chapter Objectives
You use LIST function to configure the scanner. This chapter describes the
LIST selections. Read this chapter to learn how to:
access the LIST function
configure the front panel and channel 0 through scanner number 1
configure communication channels for I/O, backup, or
peer-to-peer communication
configure communication channel 4 for I/O, DH, or
DH+ communication
Accessing the LIST Function
You can access the LIST function for the scanner through a programming
terminal or the data access panel on the PLC-3 or PLC-3/10 main chassis
(cat. nos. 1775-A1, -A3). Refer to the PLC-3 Family Programmable
Controller Installation and Operation Manual (publication 1775-6.7.1) for
detailed information on operating the LIST function.
Important: The scanner limits the number of executing LIST functions to
four for any PLC-3 or PLC-3/10 system.
Figure 2.1 shows you the parameters that you select for the scanner. You
access these selections by doing the following:
1.
Enter LIST.
The system displays the initial LIST menu.
2.
Select option 6 for MODULE STATUS.
3.
Select the number corresponding to the scanner that you want to
configure.
The system displays the following menu:
1775-S5 1
CHASSIS 0 SLOT 3
1 CHANNEL 1
2 CHANNEL 2
3 CHANNEL 3
4 CHANNEL 4
5 RACK RANGE
6 CHAN 0
7 DISPLAY
ENTER NEXT >
2-1
Chapter 2
Configuring the Scanner through LIST
The heading for this menu shows the scanner’s thumbwheel setting and
slot location in the processor chassis. Selections 6 and 7 only display for
scanner number 1. We describe these selections in the rest of this chapter.
Figure 2.1
LIST Selections for the Scanner
SystemMode
1 Test Monitor
2 Run Monitor
3 Program Load
4 Remote Enable
5 System Status
6 Module Status
Enter Next > 6
Modules
1 01 1775ME
2 01 1775L3
3 01 1775S5
Enter Next > 3
1775S5 1
Chass 1 Slot 3
1 Channel 1
2 Channel 2
3 Channel 3
4 Channel 4
5 Rack Range
6 Chan 0
7 Display
Enter Next >
S5 1Chan 1
1 Baud *57.6 115.2 230.4
2 Mode: I/O
3 Auto Config
4 Reconfiglkp
5 I/O Scan Config
6 Peer Master Config
7 Peer Slave Config
8 Backup Comm. Config
Enter Next >
S5 1Chan 4
1 Baud *57.6 115.2 230.4
2 Mode: I/O
3 Auto Config
4 Reconfig
5 I/O Scan Config
6 Peer Master Config
7 Peer Slave Config
8 Backup Config
9 DH/DH+ Config
Enter Next >
S5 1
1* 076
2 100176
3 200276
4 300376
Enter Next >
S5 1 Chan 0
1 l.T Defaults
2 Privileges
3 Baud
4 Parity *Even Odd None
5 Stopbits *1 1.5 2
6 Chan Timeout 10000 ms
7 Reconfig
Enter Next >
Front Display Privileges
3
10
67
69
70
Enter Next >
The asterisk (*) indicates the default selection
2-2
Mode Selection
1 Inactive
2* I/O
3 Peer Master
4 Peer Slave
5 Backup Comm
Enter NExt >
Mode Selection
1 Inactive
2* I/O
3 Peer Master
4 Peer Slave
5 Backup Comm
6 DH
7 DH+
Enter NExt >
Chan 0Privileges
0
2
3
4
5
6
8
10
64
65
66
68
69
70
71
72
Enter Next >
Enter Timeout >
S5 1. Chan 0 Baud
1 110 Baud
2 150 Baud
3 300 Baud
4 600 Baud
5 1200 Baud
6 1800 Baud
7 2400 Baud
8 4800 Baud
9* 9600 Baud
10 19200 Baud
S5 Chan 1 I/O
1 003/2/0
2 005/2/2
3 006/2/6/I
4 003/2/2
5 005/4/4/I/F
Enter Next >
Enter Master >
S5 Chan 1 Slaves
Slave 86
S5 Chan 1 Slave 86
Slave 82
1 Input File I1:0 → 20 → Enter Input File>
Slave 84
2 Output File O1:0 → 20 → Enter Output File>
Enter Next >
S5 Chan 1 Peer Master
1 Master 1
2 Slaves
Enter Next >
S5 Chan 1 Peer Slave
1 Slave 1
2 Master 1
3 Input File I1:0 → 50
4 Output File O1:0 → 20
Enter Next >
Enter Slave >
Enter Master >
Enter Input File >
Enter Output File >
S5 Chan 1 Backup Comm
1 Resident 1
2 Partner 2
3 Input File I1:0 → 50
4 Output File O1:0 → 20
Enter Next >
Enter Resident >
Enter Partner >
Enter Input File >
Enter Output File >
S5 1 Chan 4
1 Node Mode * Online Offline
2 Station Number: 030 Selected 030 Actual
3 DH/DH+ Timeouts
4 Backup Operation
5* Send Unprotected
6* Accept Upload/Download
7* Accept Writes
See page 216
8 Input File List
9 Privileges
10 DH/DH+ Switch Settings
11 DH+ Active Node List
12 DH+ Active Nodes To Status File 6
Enter Next >
See page 219 & 220
Enter Station Number
(Enter Leading 0 For
Octal Number) >
S5 1
DH/DH+ Timeouts
1 Outgoing Message 5.0 Sec
2 List Channel
300.0 Sec
3 Remote Program 300.0 Sec
Enter Next >
Privileges
0
3
4
5
6
8
10
64
65
66
68
69
70
71
72
74
Enter
Next >
Chapter 2
Configuring the Scanner through LIST
Configuring the
Communication Channels
To configure channels 1 through 4, you select the following parameters:
communication rate (bps) (page 2-3)
operating mode (page 2-4)
auto configuration (page 2-4)
reconfiguration (page 2-5)
I/O scan configuration (page 2-6)
peer-to-peer master configuration (page 2-8)
peer-to-peer slave configuration (page 2-8)
backup communication configuration (page 2-9)
DH or DH+ configuration (channel 4 only) (page 2-10)
Communication Rate
You can select one of the following communication rates for the
corresponding communication channel:
If you select:
Then the maximum I/O channel cable length can be:
57.6 kbps
10,000 feet
115.2 kbps
5,000 feet
230.4 kbps
2,000 feet
Important: If you are configuring channel 4, note the following:
You must set the protocol switches for LIST configurable for the
scanner to modify this selection.
For DH communication, the scanner communicates at 57.6 kbps only.
For DH+ communication, the scanner communicates at 57.6 kbps or
115.2 kbps. Not all DH+ stations are capable of operating above 57.6
kbps. You must reference the appropriate users manual for the
maximum communication rate for each device.
ATTENTION: Channel 4 cannot be configured for DH or DH+
when operating any of the other communication channels at
230.4 kbps. Otherwise, I/O rack retries and missing inputs in a
listen only mode backup system can result.
2-3
Chapter 2
Configuring the Scanner through LIST
Operating Mode
You can select one of the following operating modes for the corresponding
communication channel:
inactive
I/O scan
peer-to-peer master
peer-to-peer slave
backup communications
DH communications (channel 4 only)
DH+ communications (channel 4 only)
These selections identify what the channel is being used for. The default is
I/O scan.
An asterisk (*) displays next to the current mode of the channel. To
change the mode, you select the number that corresponds to the desired
mode and reconfigure the channel.
For channel 4, the protocol switch must be selected for LIST configurable
for you to change the operating mode through LIST (refer to “Setting the
Protocol, Communication Rate, and Station Address for Channel Four,”
page 1-7).
Important: If you are not using a communication channel, set the
operating mode for the channel to inactive. This causes the scanner to stop
communicating through the channel improving the communication times
on the other active channels.
Auto Configuration
Auto configuration first creates a new I/O chassis list in which each I/O
chassis has equal priority with no attributes assigned. Then the scanner
reconfigures.
The scanner performs an auto configure at power-up for an
I/O-scan-configured channel that has no entries in its I/O chassis scanning
sequence list.
When forming the I/O chassis list during an auto configuration, the scanner
polls all valid addresses. If the scanner receives response to an address, it
adds that address to the list. To assign attributes or priorities to the I/O
chassis, add them manually through LIST and reconfigure the channel.
2-4
Chapter 2
Configuring the Scanner through LIST
You can only perform an auto configuration when:
the controller is in program load mode
power is applied to the I/O chassis
the processor restart lockout switch is set to allow the I/O chassis to be
restarted from the processor
If power is not applied to the I/O chassis, the processor attempts to perform
an auto configure, and since the I/O chassis does not respond, the scanner
does not enter it in the I/O chassis list. For an entry to get into the I/O
chassis list in auto configure, a valid path must exist between the scanner
and the I/O adapter module for the I/O chassis.
ATTENTION: You can replace a 1775-S4A, -SR scanner with
a 1775-S5, -SR5 scanner, however, you must:
perform a logical save of memory without saving the module
status area (E2)
clear memory after replacing one scanner with another.
restore the previously stored memory
configure each 1775-S5, -SR5 scanner communication
channel in LIST.
Failure to observe this caution could result in equipment
damage and/or undesired machine operation.
Reconfiguration
The reconfiguration selection sets configuration parameters for the scanner.
The reconfigure selection implements changes that you have made in LIST
for the communication channel. For example, suppose you list an I/O
chassis 3 times in the I/O chassis scanning sequence list, and you change
the list to include that chassis 6 times. The scanner does not change its
polling sequence until you select reconfigure for the I/O channel.
Important: When selecting reconfigure, the scanner executes a
reconfiguration of the selected channel only. Also, when you power-up the
PLC-3 controller, a reconfiguration automatically executes.
If an asterisk is next to the reconfiguration selection, changes have been
requested but not implemented. Upon selecting reconfigure, the scanner
implements the changes and removes the asterisk.
2-5
Chapter 2
Configuring the Scanner through LIST
ATTENTION: Selecting reconfiguration while the controller is
in the run mode and executing block transfers could cause a bad
address fault.
If this situation occurs, you should:
Clear the bad address fault in a fault routine.
Clear the block transfer error bit.
Restart the block transfer in the ladder program
I/O Scan Configuration
When you configure an I/O channel for I/O scan, you can change the order
and priority that the scanner scans the I/O chassis. You do this by listing
the I/O chassis in the order that you want the scanner to communicate with
them. This allows you to assign a higher priority to some I/O chassis than
to others by listing the higher priority chassis more than once.
For example, suppose your I/O chassis scanning sequence list has six
entries, and entries 1 and 4 are the same. Then the scanner updates the
chassis listed as entries 1 and 4 twice as often as the other chassis.
Each I/O chassis is listed once in the default configuration at initial
power-up or after auto configure. You can alter the list to repeat a chassis
as often as desired, provided that the list contains no more than 32 entries.
An asterisk (*) appearing before an entry in the list indicates that the
corresponding I/O chassis or adapter is faulted.
To enter a chassis into the I/O chassis scanning sequence, use the format
shown in Figure 2.2.
Figure 2.2
Entering a Chassis into the I/O Chassis Scanning Sequence List
entry / rack /size / I/O group / attributes
Position of entry in the
scanning sequence list
Assigned I/O rack
number (0 3768)
Number of I/O groups in
the chassis (2, 4, 6, or 8)
2-6
I or F
I = Chassis is for inputs only
F = Major fault is declared if chassis faults
Starting I/O group
number in the chassis (0, 2, 4, or 6)
15439
Chapter 2
Configuring the Scanner through LIST
To delete entries from the list, press:
entry/d
[Return]
When forming this list, remember:
Selection of I/O rack numbers greater than 378 increases the program
scan time.
I/O rack numbers that are not assigned consecutively cause greater
memory requirements because memory has to be allocated for the
unused racks.
You can connect up to 32 I/O adapters to one I/O communication
channel on a scanner.
You can assign up to 16 different I/O rack numbers to one scanner.
For duplicate I/O addressing (complementary I/O or parallel output
configurations), you must have two chassis with the same assigned I/O
rack number and I/O group number on different I/O communication
channels of the same scanner.
Refer to the PLC-3 Family Controller Installation and Operation Manual
(publication 1775-6.7.1) for detailed information on complementary and
duplicate I/O configurations.
ATTENTION: Do not assign the same I/O rack number and
I/O group number to two chassis on the same I/O
communication channel. Failure to observe this warning could
result in equipment damage and/or unpredictable machine
operation with injury to personnel.
The controller uses assigned I/O rack numbers 778, 1778, 2778, 3778 for
internal communication. Do not assign these numbers to an I/O rack
(although you can use the associated addresses for internal storage).
For detailed information on 1/2-slot, 1-slot, and 2-slot I/O addressing
considerations, refer to the Remote I/O Adapter (Cat. No. 1771-ASB)
User’s Manual (publication 1771-6.5.83).
2-7
Chapter 2
Configuring the Scanner through LIST
PeertoPeer Master Configuration
When you configure a channel as a master on a peer-to-peer
communication channel, you must enter the following parameters:
Parameter
Description
Master number
identifies the master for communication with the slaves. Each peertopeer
communication channel can have one master only. The master number and all
slave numbers must be unique and selected from numbers 81 through 89.
Slave numbers
identify the slaves that communicate with the master. Each master can
communicate with up to 6 slaves. The slave number must be unique and
selected from numbers 81 through 89.
Input files
identify the files that receive data from each slave. You must specify an input
file for each slave in the input image section of the data table. If you do not
make a selection, the file defaults to input file 1. The files also must be large
enough to store the data from each slave's output file. If the file is not large
enough, the processor declares a minor fault.
Output files
identify the files that send data to each slave. You must specify an output file
for each slave in the output image section of the data table. If you do not make
a selection, the file defaults to output file 1.
LIST displays the size of the input and output files. For example,
I1:0 → 19 shows that input file 1 contains 20 octal words. You can create
a larger file by entering the last word desired in the file when prompted for
the file number in LIST. By entering I1:50 for the input file, the system
will automatically increase input file 1 to 50 octal words.
To delete slave entries from the list, press:
slave entry /d
[Return]
PeertoPeer Slave Configuration
When you configure a channel as a slave on a peer-to-peer communication
channel, you must enter the following parameters:
2-8
Parameter
Description
Slave number
identifies the slave that communicates with the master. The slave number must
be unique and selected from numbers 81 through 89.
Master number
identifies the master on the channel. The master number and all slave
numbers must be unique and selected from numbers 81 through 89.
Input file
identifies the file that receives data from the master. This file must be in the
input image section of the data table. If you do not make a selection, the file
defaults to input file 1. This file must be large enough to store the data from the
master's output file. Otherwise the processor sets the peertopeer minor fault
bit.
Output file
identifies the file that sends data to the master. This file must be in the output
image section of the data table. If you do not make a selection, the file defaults
to output file 1.
Chapter 2
Configuring the Scanner through LIST
LIST displays the size of the input and output files. For example,
I1:0 → 19 shows that input file 1 contains 20 octal words. You can create
a larger file by entering the last word desired in the file when prompted for
the file number in LIST. By entering I1:50 for the input file, the system
will automatically increase input file 1 to 50 octal words.
To delete slave entries from the list, press:
slave entry /d
[Return]
Backup Communications Configuration
When you configure a channel for backup communication, you must enter
the following parameters:
Parameter
Description
Resident number
identifies the system being configured on the channel. The resident number
must be different from the partner number and selected from numbers 81
through 89.
Partner number
identifies the other system on the channel. The partner number must differ
from the resident number and selected from number 81 through 89.
Input file
identifies the file that receives data from the partner. The input file must be in
the input image section of the data table. If you do not make a selection, the
file defaults to input file 1. This file must be large enough to store the data from
the partner system's output file. Otherwise, the processor sets the backup
communication minor fault bit.
Output file
identifies the file that sends data to the partner. The output file must be in the
output image section of the data table. If you do not make a selection, the file
defaults to output file 1.
LIST displays the size of the input and output files. For example,
I1:0 → 19 shows that input file 1 contains 20 octal words. You can create
a larger file by entering the last word desired in the file when prompted for
the file number in LIST. By entering I1:50 for the input file, the system
will automatically increase input file 1 to 50 octal words.
To delete slave entries from the list, press:
slave entry /d
[Return]
2-9
Chapter 2
Configuring the Scanner through LIST
DH or DH+ Configuration
When you configure channel 4 for DH or DH+ communication protocol,
you can set the following parameters:
node mode (page 2-11)
station number (page 2-11)
DH/DH+ timeouts (page 2-12)
backup operation (page 2-13)
send unprotected (page 2-14)
accept upload/download (page 2-15)
accept writes (page 2-15)
input file list (page 2-16)
privileges (page 2-17)
DH/DH+ switch settings (page 2-18)
DH+ active node list (page 2-19)
DH+ active nodes to status file 6 (page 2-20)
When configuring channel four for a communication protocol, the menu
contains these selections:
S5
1-CHAN 4
1 NODE MODE
*ON–LINE
OFF–LINE
2 STATION NUMBER:
23 SELECTED
255 ACTUAL
3 DH/DH+ TIMEOUTS
4 BACKUP OPERATION
5 *SEND UNPROTECTED
6 *ACCEPT UPLOAD/DOWNLOAD
7 *ACCEPT WRITES
8 INPUT FILE LIST
9 PRIVILEGES
10 DH/DH+ SWITCH SETTINGS
11 DH+ ACTIVE NODE LIST
12 DH+ ACTIVE NODES TO STATUS FILE 6
ENTER NEXT >
The following subsections describe these selections.
2-10
Chapter 2
Configuring the Scanner through LIST
1 - Node Mode
Select the NODE MODE option from the configuration screen to allow or
disallow the station communicating on the link. By selecting NODE MODE,
you can configure the channel to be online or offline.
If you select:
Then the channel is:
online
an active station on the link.
offline
inactive and the DH/DH+ disable indicator is turned on.
Important: A reconfigure is not necessary to change this selection. The
NODE MODE changes to the opposite selection and takes affect immediately.
An asterisk (*) displays in front of the selected modes.
2 - Station Number
Select the STATION NUMBER option from the configuration screen to
identify the PLC-3 station on the DH or DH+ link. You can specify an
octal station number by starting it with a leading 0. Otherwise, the scanner
treats it as a decimal number.
Allowable station numbers are:
for:
0 to 376 octal
DH
0 to 77 octal
DH+
The number 377 octal is illegal. Entering 377 as the station number
automatically disables the channel, and you cannot enable it again until
you select a different station number in LIST. If you make no selection,
the scanner sets the station number for 377 octal (255 decimal) by default.
Important: You must set the protocol select switches for LIST
configurable before the scanner can modify this selection.
If you set the station number by using the switches (see chapter 1), the
scanner displays that number as decimal in LIST.
This line may show two values for the station number: selected and actual.
Both numbers display if they are different, and if these two situations
occur:
you changed the station number in line 2 but have not executed a
reconfigure to change the actual station number to the new number
the scanner in a backed up system assumes an address different from the
primary scanner until switchover occurs
2-11
Chapter 2
Configuring the Scanner through LIST
3 - DH/DH+ Timeouts
Select the DH/DH+ Timeouts option to set these timeout values in seconds:
outgoing message
LIST channel
remote program
Outgoing Message
This timeout is the maximum amount of time that the scanner waits for
another station to reply to one of the messages. The valid entries are 0 to
999.9. In LIST, you can enter timeout values as whole numbers or in
tenths of seconds.
For example:
If you enter a timeout value of:
The scanner sets the timeout period for:
100
100.0 seconds
50.2
50.2 seconds
Important: If you enter 0, the processor disables the timeout parameter.
The timeout period applies to each individual transmission. Some
messages consist of several packets of data because of their size. Each
message packet requires a separate transmission. Therefore, the timeout
restarts for each packet.
LIST Channel
This timeout detects a lack of activity by a station on the link still having
an allocated LIST resource. Set this value high enough to prevent a
timeout while running LIST but not so high that a station on the link keeps
the LIST resource allocated unnecessarily.
Once this time expires, the next list selection you enter displays the initial
list menu. You can then continue through your selections.
Important: This timeout takes affect anywhere from one to two times the
value you enter through LIST.
Remote Program
This timeout detects a lack of activity by a previously connected
programming station. Should a connected programming station be
abruptly disconnected from the link, this timeout would make sure that the
edit resource and histogram resources are returned to the scanner.
Important: This timeout takes affect anywhere from one to two times the
value you enter through LIST.
2-12
Chapter 2
Configuring the Scanner through LIST
4 - Backup Operation
Select the Backup Operation option from the configuration screen to
configure the DH and DH+ station numbers when backed up. See
Table 2.A.
Table 2.A
Backup Operation Options
If backup is:
The DH and DH+ station number of the backup scanner module:
Selected
is automatically modified before and after switchover. This allows you to
have identical configurations in both the primary and the backup
processor.
Not selected
remains the same both before and after switchover. The primary and
backup processors must have unique station numbers.
Regardless of which mode you select, both the primary and the backup DH
and DH+ channels are active. There is no selection for the backup DH or
DH+ channel to remain silent on the link until switchover.
When you select backup operation, you assign the same DH or DH+
station number to both the scanner module in the primary processor and
the one in the backup processor.
As long as the primary processor is controlling the outputs, the station
address of the DH or DH+ channel in the backup processor is modified.
Table 2.B and Table 2.C show the station number modifications for DH
and DH+, respectively. At switchover, the DH or DH+ station number in
the backup processor assumes the station address assigned to it with the
LIST function.
Table 2.B
DH Station Numbers for 1775S5, SR5 Modules
If the station address between:
The backup scanner module assumes a station
address that is:
000 and 2768
1008 higher than the assigned station number
3008 and 3768
1008 lower than the assigned station number
Important: Do not give the 1775-S5, -SR5 module the reserved station
address of 3778; and, when you select the backup operation, you cannot
give the module a station address of 2778.
2-13
Chapter 2
Configuring the Scanner through LIST
Table 2.C
DH+ Station Numbers for 1775S5, SR5 Modules
If the station address between:
The backup scanner module assumes a station
address that is:
00 and 378
408 higher than the assigned station number
408 and 778
408 lower than the assigned station number
When you do not select backup, you assign a unique DH (0008 to 3768) or
DH+ (008 to 778) station number to the scanner module in the primary
processor and the one in the backup processor. The backup continues to
operate with the same station number even after the switchover.
ATTENTION: To guard against personal injury and damage to
equipment, do not assign the same station number to both
scanner modules, if you have not selected backup mode.
If both scanners are assigned the same number and backup is
not selected, two stations with the same station number attempt
to communicate on the link. This can cause unpredictable
machine motion.
5 - Send Unprotected
Select the Send Unprotected option from the configuration screen to
determine if the scanner can send unprotected command messages to other
stations. You use command messages to communicate with other
controllers on a DH or DH+ network. You can use:
an unprotected command to read or write to any area of another station’s
data table
a protected command to write to those areas of another station’s data
table specified by the station that receives the command
If you:
Then the scanner can send:
select send unprotected
both protected and unprotected commands
do not select send unprotected
protected commands only
An asterisk displays in front of this selection to indicate that it is enabled.
2-14
Chapter 2
Configuring the Scanner through LIST
6 - Accept Upload/Download
Select the Accept Upload/Download option from the configuration screen
to determine if the scanner can execute upload and download commands
sent by another station. You use a sequence of upload and download
commands to transfer memory information from the controller to another
station or from another station to the controller.
If you:
Then the scanner:
select accept upload/download
can execute both upload and download commands
do not select accept
upload/download
cannot execute upload and download commands
An asterisk (*) displays in front of this selection to indicate that it
is selected.
7 - Accept Writes
Select the Accept Writes option from the configuration screen to
determine if the scanner accepts write commands sent by a remote station.
If you:
Then the scanner:
select accept writes
accepts write commands if the channel has the privilege to
write to the specified memory area, and the assigned privilege
is independent of the memory protect keyswitch (see
Privileges", page 217)
do not select accept writes does not accept write commands under any condition
If the assigned privilege is not independent of the keyswitch, the scanner
checks the keyswitch position before writing:
If the keyswitch is set to:
Then the scanner:
memory protect on
does not accept write commands and generates
error code 86 (see appendix B)
data change or memory protect off
accepts write commands
An asterisk (*) displays in front of this selection to indicate that it
is selected.
2-15
Chapter 2
Configuring the Scanner through LIST
8 - Input File List (PLC2 Compatibility Mode Only)
Select the Input File List option from the configuration screen for a list
of files that the scanner accesses when receiving data using PLC-2 logical
data addressing (see chapter 5). When a PLC-2 command comes in from a
station on a DH or DH+ link, the scanner accesses the input file associated
with that remote station number. You must make sure the input file is
created in memory.
If you do not list an input file for a remote station, the scanner assigns a
default file to it. The default file number matches the remote station
number (except for remote station zero which is assigned input file 8):
PLC2 compatible remote
station number in octal
Assigned input file for
read/write access
000
001
002
003
004
005
006
007
010
011
012
.
.
.
077
100
I008
I001
I002
I003
I004
I005
I006
I007
I010
I011
I012
.
.
.
I077
I100
Station address 000 is assigned to input file I008. Otherwise PLC-3 input
files with an 8 or 9 in their addresses are not used for read/write access by
a PLC-2 station.
If you do not want to use the default input file, you can use the input file
list selection. Upon selecting input file list, the list of remote station
addresses and associated input files displays. Initially, the list is empty and
default assignments do not display unless you enter them.
Important: You can assign a remote station to only one input file, but you
can assign different remote stations to the same input file.
2-16
Chapter 2
Configuring the Scanner through LIST
To add a station address and input file to the list, enter a colon (:) followed
by the station address, a space, and the input file number. For example:
INPUT FILE LIST
STATION
FILE
:0
2
:5
2
:64
6
:65
7
1:37
4
ENTER STATION AND INPUT FILE #> :6 4
You can specify an octal station number by starting it with a leading 0.
Otherwise, the scanner treats it as a decimal number. The file number is
always treated as a decimal number.
To specify station addresses for stations on remote links, you can enter:
link:node
To remove a station from the list, enter the station number followed by /D.
For example:
ENTER STATION AND INPUT FILE #> 1:37/D
This example removes link 1, station number 37 from the input file list.
Another example:
ENTER STATION AND INPUT FILE #> :5/D
This example removes station number 5 from the input file list.
9 - Privileges
Select the Privileges option from the configuration screen to select
operating parameters for the DH/DH+ communication channel. These
operating parameters are called privileges.
For example, you must have privilege 4 selected in order to enter and edit a
ladder program. If you want to protect your ladder program from editing,
you could deselect privilege 4. Another user could still monitor or read
your ladder program, but could not alter it.
2-17
Chapter 2
Configuring the Scanner through LIST
Available privileges are:
Privilege
Number
0
1
2
3
4
5
6
7
8
10
64
65
66
67
68
69
70
71
72
73
74
Allows the device on the channel to
write to the system status area of memory
write to the system pointers area of memory
write to the module status area of memory
write to the data table area of memory
write to the ladder program area of memory
write to the message area of memory
write to the system symbols area of memory
write to the system scratchpad area of memory
write to the converted procedures area of memory
write to the force tables area of memory
Online edit or edit the ladder program while the processor is in the run mode
Create and delete sections of memory
Change privileges list
Change the operating mode without having the remote enable section in LIST
active
Change the operating mode only when the remote enable selection in LIST is
active
Change system parameters in LIST such as system clock, watchdog timer, and
current context
Change module dependent parameters in LIST
Test the ladder program by putting the processor in test mode
Perform a physical write
Accept keyboard input for GA Basic, report generation, or message procedure
commands. By removing privilege 73, you can prevent an operator or other
device, such as a bar code reader, from allocating a device on the channel.
Abort a GA Basic task in LIST
To modify a privilege, do the following:
If you want to:
Then:
add a privilege
enter the privilege number
make a privilege independent of the memory
protect keyswitch
enter the privilege number followed by /I
remove a privilege
enter the privilege number followed by /D
10 - DH/DH+ Switch Settings
You can determine the state of the DH/DH+ switch settings without
removing the scanner from the chassis. Select the DH/DH+ Switch
Settings from the configuration screen to determine the state of the
DH/DH+ switch settings.
2-18
Chapter 2
Configuring the Scanner through LIST
When you select this option, the programming terminal displays:
DH/DH+ SET-UP SWITCH SETTINGS
(VIEW FROM TOP OF MODULE)
S1
DOWN/ON
X
X
UP/OFF
SWITCH #
8
7
S2
X
X
X
6
5
4
X
X
3
X
X
2
1
1 EXIT THIS MENU
ENTER NEXT >
4
63
NOTE:
X
2
1
X
STATION NUMBER IN OCTAL
CURRENT SELECTION
X
MODULE
FRONT
3
MODE
BAUD
DH+
57.6KB
SWITCH CHANGES ARE ONLY READ AFTER POWER-UP
11 - DH+ Active Node List
Select the DH+ Active Node List option from the configuration screen to
display a list of active nodes on the local link for channel four:
an X next to a station number indicates a remote station on the link.
a US next to a station number indicates the station number of the scanner
whose list configuration you are currently viewing.
LIST OF ACTIVE STATIONS ON THE LOCAL DH+ LINK
TOTAL NUMBER OF STATIONS ON LOCAL LINK
0
X
10
20
30
40
50
60
70
1
X
11
21
31
41
51
61
71
2
X
12
22
32
42
52
62
72
3
X
13
23
33
43
53
63
73
4
X
14
24
34
44
54
64
74
5
X
15
25
35
45
55
65
75
6
US
16
26
36
46
56
66
76
17
27
37
47
57
67
77
7
1
7
EXIT THIS MENU
2 REDISPLAY MENU
2-19
Chapter 2
Configuring the Scanner through LIST
12 - DH+ Active Nodes to Status File 6
Select the DH+ Active Nodes to Status File 6 option from the
configuration screen to maintain the DH+ active node table in status file 6.
The list of active nodes is stored in status file 6. If you enable this option,
you must also create status file 6.
Status file 6 is partitioned into 4 words for each of the 15 possible scanner
thumbwheels. To provide for 15 scanners, you must create S6:59. Each of
the 64 bits contained in the 4 word groups represent the possible DH+
station numbers of 0 through 77 octal.
If the bit is a:
Then the station represented by that bit is:
1
active on the link.
0
not on the link.
Important: This table is updated even when the system is in
program mode.
Setting the Rack Range
The rack range selection in LIST sets the range of assigned I/O rack
numbers. The default setting for the rack number range is 0-768.
If you plan to use rack numbers greater than 378, consider the following:
Each instruction in the ladder program that addresses an input or output
in a rack greater than 378 uses one additional word of memory and
increases the program scan time. Typically, the program scan increases
about 0.01 milliseconds for each relay logic instruction (XIC, XIO,
OTE, OTL, OTU) that address a bit in a rack greater than 378.
The amount of memory required for the input and output sections
depends on the highest rack number containing input or outputs
respectively. Therefore, skipping rack numbers wastes memory.
Configuring the Front Panel
2-20
The list configurable items for scanner number 1 also include selections for
front panel channel 0, and the front panel data access display.
Select:
To enable you to set:
channel 0
parameters for the RS232C port labeled CHANNEL 0 on the front panel.
The parameter selections are described in the following sections.
display
the privileges for the front panel display. These privileges determine what
you are allowed to accomplish through the front panel keypad. The
default for these privileges is 3, 10, 67, 69, and 70.
Chapter 2
Configuring the Scanner through LIST
I.T. Defaults / Configuration
The I.T. defaults selection in LIST configures channel 0 for Binary
Command Language (BCL) protocol communication with an industrial
terminal (see appendix A). You can use the industrial terminal as a
programming terminal for such functions as ladder programming. When
you select I.T. defaults, the default values are used as shown in the
following table.
The remaining configuration selections allow you to modify the front
panel parameters shown in the following table to something other than
their default settings.
Characteristic
Description
Default
privileges
This selection allows you to select operating parameters for channel 0. Refer to the section
entitled Privileges" under DH or DH+ Configuration" on page 217 for a full description of
the privileges and how to assign them.
0, 2, 3, 4, 5, 6, 8,
10, 64, 65, 66, 68,
69, 70, 71, 72
communication rate
The rate at which the RS232C device communicates to the processor through channel 0 is
the communication rate. You can select one of the following communication rates:
• 110 bps
• 150 bps
• 300 bps
• 600 bps
• 1200 bps
• 1800 bps
• 2400 bps
• 4800 bps
• 9600 bps
• 19200 bps
Set the communication rate by typing the number corresponding to the desired rate. An
asterisk displays next to the current communication rate.
9600 bps
parity
You can configure channel 0 to communicate using the following parity selections:
• even
the channel transmits an even parity bit with each character and checks for an even
parity bit in each character received
• odd
the channel transmits an odd parity bit with each character and checks for an odd
parity bit in each character received
• none
the channel does not transmit a parity bit and does not check for parity bits
An asterisk (*) displays next to the current parity state.
even
stop bits
You can specify the number of stop bits that channel 0 uses to communicate. The stop bit
selections are 1, 1.5, and 2. An asterisk displays next to the current stop bit selection. To
change the number of stop bits, type the number corresponding to the desired selection.
1
channel timeout
You can specify the amount of time that the processor allows between operations on a
channel before terminating communication. This amount can be set up to a maximum of
32,767ms (32.767s). If you want to disable the timeout function, set the value to 0.
10,000 ms
2-21
Chapter 2
Configuring the Scanner through LIST
Reconfiguration
This selection implements changes that you have made in LIST for channel
0. If channel 0 is being used when you reconfigure it, the changes are not
implemented until communication on the channel is terminated and then
re-established.
An asterisk appears next to Reconfigure when a change has been made to
any of the channel 0 parameters. The asterisk is removed after a successful
reconfigure.
2-22
Chapter
3
I/O Communication
Chapter Objectives
This chapter describes timing and programming considerations when using
the scanner for I/O communication and helps you learn how:
I/O scan affects ladder program execution
to calculate block-transfer times
to program and calculate times for a peer-to-peer or backup
communication channel
Effect of I/O Scan on
Program Execution
You must remember that in scanning the ladder program and the I/O:
input changes do not instantly appear in the input image table. The
length of time between an input change and the update of the input table
depends on the input module delay, the signal propagation time,
backplane access time, and the I/O scan time.
the I/O scan is not synchronized with the ladder program scan.
Therefore, the same inputs can be in different states at different times
during the program scan.
Calculating the I/O Scan Time
The amount of time that the scanner takes to scan all the I/O on a given
channel depends on the communication rate and the number of:
entries in the I/O chassis scanning sequence list
active channels on the scanner
block transfers
retries required due to noise
Table 3.A shows the scan times for one I/O adapter on each active channel
with no block transfers.
3-1
Chapter 3
I/O Communication
Table 3.A
I/O Scan per I/O Chassis in Milliseconds
Number of Active I/O Channels
bps
Chan 4 Config
1
2
3
4
57.6k
Not DH/DH+
DH/DH+
7
8
7
8
7.5
9
8
N/A
115.2k
Not DH/DH+
DH/DH+
4.5
5
5
6
5
7
6.5
N/A
230.4k
Not DH/DH+
DH/DH+
3
N/A
3.5
N/A
5
N/A
6
N/A
Each I/O chassis that you add to the scanning sequence list (including
repeated I/O chassis in the list) increases the I/O scan time.
When you add block-transfer modules to the channel, the I/O scan time
increases by approximately 1ms per adapter on all channels while the
scanner executes the block-transfer instruction.
Calculating BlockTransfer Times
The time required to complete a block transfer depends on the number of:
I/O channels on the scanner that contain block-transfer I/O modules
active I/O channels on the scanner
entries in the I/O chassis scanning sequence list for the channel
block-transfer I/O modules on the channel
To calculate the time required for the scanner to execute all block transfers
on the channel and be ready to execute the block-transfer again:
3-2
1.
Determine the number of active I/O channels on the scanner.
2.
Determine the number of I/O channels with block-transfer
I/O modules.
3.
Determine the nominal block-transfer time (see Table 3.B).
Chapter 3
I/O Communication
Table 3.B
NominalBlockTransfer Times in Milliseconds for a Blocktransfer
Instruction
Channels with block
transfer I/O modules
Number of active channels
1
2
3
4
1
27
27
28
35
2
x
29
30
36
3
x
x
31
38
4
x
x
x
40
4.
Count the number of block-transfer I/O modules on the channel. If
the chassis containing a block-transfer I/O module appears more than
once in the I/O chassis scanning list, count the module once each time
the chassis appears in the list.
5.
Count the number of entries in the I/O chassis scanning sequence list
for the channel.
6.
Calculate the time between block transfers as follows:
T = (NBT x NM)ms + (NE – 1) x 7ms
PeertoPeer and Backup
Communication
Where:
Is the:
T
time between block transfers
NBT
nominal blocktransfer time (Table 3.B)
NM
number of blocktransfer modules (step 4)
NE
number of entries in the I/O scan list
PLC-3 family controllers can communicate with other PLC-3 family
controllers using peer-to-peer or backup communication channels.
PeertoPeer Communication
A peer-to-peer communication channel includes one PLC-3 or PLC-3/10
controller configured as the master and up to six PLC-3 or PLC-3/10
controllers configured as slaves. The master communicates with all slaves
on the channel, while each slave communicates only with the master
(Figure 3.1).
Also, when configured in a backup system, the backup slave receives all
input data that are sent to the primary slave if the slave numbers are
the same.
3-3
Chapter 3
I/O Communication
Figure 3.1
Using a PeertoPeer Communication Channel
Slave A
Master
Slave B
Twinaxial cable for setting up
peertopeer communication channel.
15410
You configure the master and slave controllers for the peer-to-peer channel
through LIST. Communication occurs via files that you specify in LIST.
Figure 3.2 shows the communication flow between master and slave
controllers on a peer-to-peer channel.
Figure 3.2
Communication Flow Between Master and Slave Controllers on a
PeertoPeer Communication Channel
Slave A
Processor
Memory
Master
Slave B
Processor
Memory
Processor
Memory
input file
output file A
output file B
input file
output file
input file A
input file B
output file
Processor
Memory
Each input file must be large enough to store the data from the
corresponding output file. Otherwise, a peertopeer communication minor
fault occurs.
3-4
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Chapter 3
I/O Communication
Programming PeertoPeer Communication
Programming PLC-3 family controllers for peer-to-peer communication
requires that the ladder program in the:
master transfers the appropriate data to its output file
receiving slave knows the proper use for each word in its input file
The controller automatically handles the actual data transfer. Each slave’s
input file must be equal to or larger than the master’s output file.
Otherwise, a peer-to-peer communication minor fault occurs.
Figure 3.3 shows an example of the ladder rungs that transfer data to
output file FO001 in the master controller. The rungs that move data into
the output file are unconditional. If they are conditioned, “old” data
transfers whenever the rung conditions are false, because the transfer
occurs regardless of whether the output file is updated.
Figure 3.3
Example Rungs in the Transmitting Controller on a PeertoPeer
Communication Channel
CTU
I0001
01
COUNT UP C0008
CP =
CA =
10
6
C0008
CU
17
C0008
DN
15
MOV
MOVE FROM A TO R
A : WCACC:0008
6
R : WO001:005
0000000000000110
MVF
FILES FROM A TO R
A : FB001:0000
R : FO001:0010
COUNTER : C0009
POS/LEN = 0/ 10
MODE = ALL/SCAN
C0009
EN
12
C0009
DN
12
C0009
ER
12
3-5
Chapter 3
I/O Communication
Important: You can control the information that is transferred by using
multiple rungs to transfer different information to the output file,
depending on the rung conditions. However, remember that the output file
contains only the last data that moves into each location.
The peer-to-peer transfer is independent of program scan and a file can be
transferred before being fully updated by the ladder program.
Figure 3.4 shows an example of the ladder rungs that receive data in input
file FI001. Data in the input file of the receiving controller corresponds to
the data in the output file of the transmitting controller.
In the example rungs shown in Figure 3.3 and Figure 3.4:
input word 5 of the receiving controller reflects accumulated value for
counter 8 in the transmitting controller
the first 10 words of binary file 1 in the receiving controller reflect the
status of the corresponding words in the transmitting controller
In both examples, remember that either the transmitting or receiving
controller could be the master, provided that the other controller is a slave.
The master communicates with each slave on the channel, but the slaves
communicate only with the master.
Figure 3.4
Example Rungs in the Receiving Controller on a Peertopeer
Communication Channel
EQU
00007
A = B
A : WI001:0005
0000000000000110
B : WN001:0002
6
12
MVF
FILES FROM A TO R
A : FI001:0010
R : FB001:0000
COUNTER : C0009
POS/LEN = 0/ 10
MODE = ALL/SCAN
3-6
C0009
EN
12
C0009
DN
15
C0009
ER
13
Chapter 3
I/O Communication
Important: Remember to reset the counter for the MVF, or the move
operation does not function properly.
Backup Communication
You can use the backup communication with the PLC-3 or PLC-3/10
backup feature. The backup feature has an I/O listening mode that enables
the backup system to monitor input data. To transfer other information to
the backup system, you can install a backup communication channel
(Figure 3.5).
With a backup communication channel, you can program data transfers
between the primary and backup controller (Figure 3.5). Then, when the
primary controller shuts down, the backup controller has up-to-date data
for running your application. Such data could be storage, block transfer,
timer, or counter information.
Figure 3.5
Using a Backup Communication Channel
Primary System
Backup System
Backup cable for
setting up type of
switchover.
Twinaxial cable for setting
up backup communication
channel.
15412
Important: You cannot use peer-to-peer communication to
communication between the primary and backup system because the
backup processor listens but does not respond to communication received
on a peer-to-peer communication channel.
You configure the primary and backup controllers for the backup
communication channel through LIST. Communication occurs via files
that you specify in LIST (Figure 3.6).
3-7
Chapter 3
I/O Communication
Figure 3.6
Communication Flow Between Primary and Backup Controllers on a
Backup Communication Channel
Primary System
Processor Memory
Backup System
Processor Memory
output file
input file
input file
output file
Each input file must be large enough to store the data from the
corresponding output file. Otherwise, a backup communication minor fault occurs.
15413
A backup communication channel also prevents contention over the I/O
channel should the backup cable break or become disconnected. If such a
situation occurs, the system with the highest resident number takes control
over the I/O. You assign the resident and partner numbers (see chapter 2).
Installation of peer-to-peer and backup communication channels is
described in the PLC-3 Family Controller Installation and Operations
Manual (publication 1775-6.7.1) and PLC-3 Programmable Controller
Backup Systems Manual (Publication 1775-6.3.1).
Programming Backup Communication
Backup communication channels operate in the same manner as
peer-to-peer communication channels with these considerations:
In using a backup communication channel, you can send information
back and forth between the primary and backup systems. Since
information moves both ways, you can monitor the run/backup bit (data
table status section, file 0, word 3, bit 17) to determine whether to use
the received data.
The input file in the backup system must be equal to or larger than the
output file in the primary system. Otherwise a backup communication
minor fault occurs.
3-8
Chapter 3
I/O Communication
Figure 3.7 shows example rungs using the run/backup bit (S000:3/17). To
use these rungs for backup communication, you must enter them into the
primary and backup systems. The run/backup bit is set in the primary
system and reset in the backup system. The counter is updated only in the
backup system.
In this example, both the primary and backup systems use input file 1 as
the input file and output file 1 as the output file for the backup
communication channel. For detailed information on the backup feature,
refer to the PLC-3 Family Controller Backup Concepts Manual
(publication 1775-6.3.1).
Figure 3.7
Example Rungs for a Backup Communication Channel
S0003
17
S0003
17
MOV
MOVE FROM A TO R
A : WCACC:0001
25
R : W0001:0007
0000000000011001
MOV
MOVE FROM A TO R
A : WI001:0007
0000000000011001
R : WCACC:0001
25
3-9
Chapter 3
I/O Communication
Calculating PeertoPeer and Backup Communication Times
The time required to transfer a file across a peer-to-peer or backup
communication link depends on the number of:
active channels on the scanner
communication rate
words in the output files
To calculate the time needed to update every input file on the link, use the
following procedure:
1.
Determine the number of words in all output files of the master and
each slave on the peer-to-peer communication link. Add them, divide
by 16, and round up to the nearest whole number.
Important: Remember that the master has an output file for
each slave.
2.
Determine the greatest number of active channels on any scanner on
the peer-to-peer communication channel.
3.
Find the nominal peer-to-peer time by using Table 3.C and the result
of step 2.
Table 3.C
PeertoPeer and Backup Communication Times per Slave
in Milliseconds
Number of Active I/O Channels
bps
4.
Chan 4 Config
1
2
3
4
57.6k
Not DH/DH+
DH/DH+
12
12.5
12
14
12.5
14
13
N/A
115.2k
Not DH/DH+
DH/DH+
8
9
8.5
10
9
11
10.5
N/A
230.4k
Not DH/DH+
DH/DH+
6.5
N/A
7
N/A
8
N/A
9
N/A
Multiply the result of step 3 by the result of step 1.
Update Time = (Nominal time) x (total words/16)
3-10
Chapter 3
I/O Communication
To calculate the time needed to update a specific input file on the
peer-to-peer or backup communication link, use the following procedure:
1.
Determine the number of words in the output file being sent to this
specific input file. Divide by 8 and round up.
2.
Determine the total number of slaves on the link.
3.
Determine the greatest number of active channels on any scanner on
the peer-to-peer communication link.
4.
Find the nominal peer-to-peer time by using Table 3.C and the result
of step 2.
5.
Multiply the results of steps 1, 2 and 4.
Update time = (Nominal time) x (output words/8) x
(number of slaves)
Figure 3.8 shows an example of 3 PLC-3 controllers using peer-to-peer
communication to communicate with each other on one channel and with
other PLC-3 controllers on other channels. For this example, assume that
each output file has 200 words.
3-11
Chapter 3
I/O Communication
Figure 3.8
Example Configuration for a PeertoPeer Communication Channel
PeertoPeer
Communication
Channel A
Processor A
(Master)
PeertoPeer
Communication
Channel A
Processor B
(Slave)
Processor C
(Slave)
PeertoPeer
Communication
Channel
I/O
Channel
PeertoPeer
Communication
Channel
I/O
Channels
PeertoPeer
Communication
Channels
Note: All PeertoPeer and I/O Channels connect to the
Terminal Swing Arm of the Scanner Module as shown in Figure 1.11.
I/O
Channels
10741
To calculate the time required to send 200 words from the master to both
slaves and have 200 words returned from each slave, use the following
procedure:
3-12
1.
400 words (Two 200-word output files in master)
400 words (One 200-word output file in each slave)
800 words/16 and rounding up = 50.
2.
All the scanners used for peer-to-peer communication channel A have
4 active channels.
3.
From Table 3.C, the nominal peer-to-peer time for 4 active channels
and a communication rate of 115.2k is 10.5ms.
4.
Update time = 10.5ms x 50 = 525ms.
Chapter
4
DH and DH+ Communication
Chapter Objectives
This chapter introduces some of the concepts and terminology involved
with operating the scanner on a DH or DH+ communication.
Introduction
The Allen-Bradley DH and DH+ links are communication networks for
industrial control applications. Both links consist of a central trunkline
cable that can be up to 10,000 feet long. This cable can link together as
many as 64 distinct communication points (or nodes) called stations
(Figure 4.1).
Each station consists of some type of processor and a station interface
module. The station interface module enables the processor to
communicate with other stations on the DH or DH+ link. The scanner is
the station interface module for PLC-3 family controllers. Table 4.A lists
combinations of station interface modules and controllers.
4-1
Chapter 4
DH and DH+ Communication
Table 4.A
Devices the Scanner Can Communicate with Across the DH and DH+
Network
With this link type:
You can communicate with a:
Using this device:
DH
PLC2 processor
1771KA interface module
1171KA2 communication
adapter module
PLC3 processor
1775S5 scanner
1775KA interface module
PLC3/10 processor
1775SR5 scanner
1775KA interface module
PLC5/250 processor
5130RM module
5130KA module
Computer interface using DF1
protocol
1770KF2 interface module
1771KE interface module
1771KF interface module
DH+ bridge interface
1785KA interface module
DF1, Master, or Slave bridge
interface
1770KF2 interface module
1771KE interface module
1771KF interface module
PLC2 processor
1785KA3 communication
adapter module
PLC3 processor
1775S5 scanner
PLC3/10 processor
1775SR5 scanner
PLC5 processor
PLC5
PLC5/250 processor
5130RM module
5130KA module
Computer interface using DF1
protocol
1785KE interface module
1770KF2/B interface module
DH bridge interface
1785KA interface module
DH ll bridge interface
1779KP5 foreign device
interface module
DF1, Master. or Slave bridge
interface
1785KE interface module
1770KF2/B interface module
DH+
4-2
Chapter 4
DH and DH+ Communication
Figure 4.1
Example DH and DH+ Configurations
Data Highway (DH) Link
PLC5
Family Controller
Computer
1775S5
Scanner
1785KA
Module
PLC3
Controller
1770KF2
Module
DH
Link
1770KF2
Module
PLC3 or
PLC3/10
Controller
Advisor 2+
Color
Graphic
System
PLC3/10
Controller
1775SR5
Scanner
1775KA
Module
Data Highway Plus (DH+) Link
PLC5
Family
Controller
Computer
1775S5
Scanner
PLC3
Controller
1770KF2
Series B
Module
DH+
Link
1770KF2
Series B
Module
Advisor 2+
Color
Graphic
System
PLC3/10
Controller
1784T50
Terminal
1775SR5
Scanner
15272
4-3
Chapter 4
DH and DH+ Communication
Communication Terms
Stations communicate with each other by sending two types of messages
over a link:
Type of messages:
Function:
command messages
either gives (writes) data to, or requests (reads) data from one
station to another.
reply messages
is a station's response to a command message.
You program command messages into the scanner. Execution of a
message command is controlled by the message (MSG) instruction in the
ladder program. When a scanner receives a command message from
another station, the module automatically generates the appropriate reply
message.
The local station is the one currently initiating some actions, or the one we
are currently doing something with. All other stations are then remote.
We can also describe stations in terms of their relationship to a message.
Solicited and Unsolicited
Messages
The station that:
Is the:
sends the message
transmitting station
gets the message
receiving station
transmits a command message
command station
transmits a reply message
reply station
The scanner can receive solicited and unsolicited messages depending on
whether the message is a command from a remote station or a reply to a
command from the local station.
If the local station issues the command message, the corresponding
reply message is said to be solicited because the local station has
solicited, or requested the data contained in the reply message.
If a remote station issues the command message, that message is said to
be unsolicited.
Either station initiates the data transfer by issuing a command message.
4-4
For
a local station receives data
from a remote station during a
and a local station sends data
to a remote station during a
solicited messages
read operation
write operation
unsolicited messages
write operation
read operation
Chapter 4
DH and DH+ Communication
In read operations, the command message requests the data transfer, but the
corresponding reply message actually contains the data being transferred.
In write operations, the command message contains the data being
transferred, and the reply message merely reports the status (receipt or
non-receipt) of the transfer.
Levels of Programming
The PLC-3 processor must be free to control its own processes at the same
time that the scanner is communicating over a DH or DH+. For this
reason, both the processor and the scanner have their own programs and
programming languages. Figure 4.2 illustrates how these two
programming levels (processor and scanner) interrelate.
Figure 4.2
Levels of Programming in DH or DH+ Communication
1) PLC3 Processor
2) 1775S5 Module
Ladder Diagram Program
Data Highway Message Procedure
PROC_A
STAT
EN
12
MSG
10012
01
MESSAGE TYPE 1
CTL = FB200:0000=200
CHANNEL: E2.3.1
STAT
DN
15
@PROC_A
STAT
ER
13
#H024$B12:37 = 15
Message procedure command
to transmit a message to data
highway station number 24
Message instruction to
execute message procedure
PROC_A
3) Data Highway
DST
SRC
CMD
STS
TNSW
ADDR
SIZE
DATA
(OPTIONAL)
Command message transmitted to station 24
4-5
Chapter 4
DH and DH+ Communication
Ladder Program
The first link in the communication process is your ladder program. You
send a DH/DH+ command message by means of the message (MSG)
instruction (Figure 4.2).
When the rung becomes true, the processor informs the scanner to begin
sending command(s) across the link. At the same time, bits in a control
file word change their state (Table 4.B) to reflect the status of the
message instruction.
Important: Once enabled, even if the rung becomes false, the scanner
continues to send commands across the DH/DH+ network until the
message is done or errors.
Table 4.B
The Status of Bits in a Control File Word
When the:
The processor:
message instruction is true
sets the enable bit (16) and the latchenable
bit (12)
scanner receives the message instruction
sets the request bit (17)
scanner begins operation
sets the busy bit (14)
scanner completes operation
resets the busy bit (14) and sets either the
done bit (15) or the error bit (13)
rung becomes false
resets the request bit (17), busy bit (140),
enable bit (16), and the latchenable bit (12)
rung becomes true a second time
resets the done bit (15) or the error bit (13)
message errors appear
sets the error bit (13) and records the error
code in bits 00 thru 07
You can program the message instruction with either:
a single message command (see chapter 6) that can be up to 76
characters long.
the name of a DH/DH+ message procedure that contains a group of
commands and is stored in the message area of PLC-3 or
PLC-3/10 memory.
4-6
Chapter 4
DH and DH+ Communication
You specify the scanner that receives the command with an
extended address.
This address always takes the form:
E2.3.nn
Where:
Function:
E2
specifies that this command addresses the modulestatus area of
memory
3
specifies that you are sending the message instruction through the
scanner
nn
is replaced with the thumbwheel setting on your particular scanner
(115)
To enter a message instruction, do the following:
1.
Enter a condition that, when true, activates the message instruction.
In Figure 4.2, we use an examine-on for input word 12, bit 01.
2.
Enter MSG for the message instruction.
3.
Choose a control file where status information about the message
command can be stored. The file should also be binary. In
Figure 4.2, we use binary file 200, word 0.
4.
Enter an extended address for the channel. In Figure 4.2, we address
the module status area of memory, specify the scanner, and a
thumbwheel setting of 1.
5.
Specify message type 1.
6.
Enter either a command or a command procedure. Figure 4.2 uses
the command procedure PROC_A.
DH/DH+ Message Procedure
The scanner has its own programming language that consists of commands
(see chapter 6). A group of related commands make up a DH/DH+
message procedure. These commands and message procedures determine
what messages are transmitted over the DH or DH+ link.
4-7
Chapter 4
DH and DH+ Communication
Data Transfers
The purpose of DH/DH+ communication is to transfer data from one
station processor memory location to another. To accomplish these data
transfers, you can program the assignment command into the scanner.
Figure 4.3 is an example of an assignment command line. For details, see
chapter 5. Since the following example does not specify a remote station,
this transfer occurs within the local systems memory.
Figure 4.3
Example Assignment Command Line
$B45:21 = $I12:33
Source Address
Address Delimiter
Assignment Command
Destination Address
Address Delimiter
11233
In the above example (Figure 4.3), the assignment command copies a word
(16 bits) of data from the source to the destination location. The source of
the data is always specified on the right of the equal sign (=), and the
destination is always on the left.
An assignment command does not destroy the data at the source location; it
copies the source data at the destination location. When the assignment
executes, both the source and destination contain the same data.
You can use a data transfer command with the scanner:
as a single command within a message instruction
as one of multiple commands within a message procedure
Figure 4.4 illustrates both of these methods for the same assignment
command. A message instruction in the ladder program controls execution
of the command in either case.
4-8
Chapter 4
DH and DH+ Communication
Figure 4.4
Two Ways to Use Message Commands
1) as a single command
in a PLC-3 message instruction
MSG
10012
01
MESSAGE TYPE 1
CTL = FB200:0000=200
CHANNEL: E2.3.1
$B45:21=$112:33
2) as part of a message procedure
Message Procedure PROC_A
STAT
EN
12
(other commands)
STAT
DN
15
STAT
ER
13
$B45:21 = $112:33
(other commands)
PLC-3 Message Instruction to Control
Execution of Procedure PROC_A
MSG
10012
01
MESSAGE TYPE 1
CTL = BW200:0000=200
CHANNEL: E2.3.1
@ PROC_A
STAT
EN
12
STAT
DN
15
STAT
ER
13
15415
Access Privileges
Not every station can read or write to every other station. In general, read
and write access privileges depend on two factors:
type of processor at the transmitting and receiving stations
protections set at the receiving station
The rest of this section explains how these access privileges vary according
to the above factors.
PLC-3 Stations
PLC-3 stations can read and write to other PLC-3 station data tables. A
local PLC-3 station can prevent remote PLC-3 stations from writing to the
local station’s data table by setting the memory protect keyswitch.
To allow writes to local memory depending on the memory protect
keyswitch setting, select Accept Writes in the DH/DH+ options menu in
LIST at the local station.
4-9
Chapter 4
DH and DH+ Communication
PLC-2 Stations
For communication with a PLC-2 station, write access privilege depends
on switch settings at that remote station. For an explanation on how to set
the switches for write access, refer to the Communication Adapter Module
User’s Manual (publication 1771-6.5.1).
Accessing a PLC-2 Station
Access to a PLC-2 station also depends on the type of command
transmitted to that station. There are two types of commands:
protected write commands –– can only write to specified sections of
the data table in a PLC-2 processor. Memory-access rungs in the PLC-2
ladder program specify where in the data table the PLC-3 can write data.
unprotected read and write commands–– can read or write to any
section of the data table at a PLC-2 station. Refer to publication
1771-6.5.1 for an explanation of protected and unprotected commands
and memory access rungs.
A PLC-3 station can read from any part of a PLC-2 data table. However, a
PLC-3 station cannot write to a PLC-2 station if the switch settings at the
PLC-2 station do not allow access.
4-10
If the switches at the PLC2
station are set to accept only:
then a PLC3 station can write
to the PLC2 data table in:
by transmitting:
protected write commands
memory areas defined by the
PLC2 ladder program
protected write
commands.
unprotected write commands
any area of the data table
unprotected write
commands.
Chapter 4
DH and DH+ Communication
Accessing a PLC-3 Processor from a PLC-2 Processor
While a PLC-3 controller can address any area of a PLC-2 data table, a
PLC-2 reads an input file that is a part of the PLC-3 data table. That file is
the PLC-3 input file with a number that corresponds to the station number
of the PLC-2 station. For example, the read/write files assigned to PLC-2
stations 1 to 100 (octal) is:
PLC2 compatible station number in octal
Assigned input file for read/write access
000
I008
001
I001
002
I002
003
I003
004
I004
005
I005
006
I006
007
I007
010
I010
011
I011
012
I012
.
.
.
.
.
.
077
I077
100
I100
Station address 000 is assigned to input file I008. Otherwise PLC-3 input
files with an 8 or 9 in their addresses are not used for read/write access by
a PLC-2 station.
The PLC-2 station can use either protected or unprotected commands to
access its assigned PLC-3 file. However, the PLC-2 station cannot access
its assigned file until that file is created and allocated at the PLC-3 station.
To create a file, refer to the user’s manual for your programming terminal.
You can have two PLC-3 stations communicate with each other as if they
were PLC-2 stations. To do this, allocate the appropriate PLC-2
addressing format (see chapter 5) in the assignment commands. Similarly,
a computer can send PLC-2 commands to a PLC-3 station by using the
appropriate message packet formats.
4-11
Chapter 4
DH and DH+ Communication
PLC-4 Stations
PLC-4 stations can only communicate on a DH. To read or write to a
PLC-4 station, you can send either protected or unprotected commands.
Switches:
at the 1773KA module specify whether the PLC4 station
accepts unprotected or protected commands, respectively
through the:
2 and 3 (on the second
row of switches)
DH port of the 1773KA module.
1 and 3 (on the third row
of switches)
RS232C port of the 1773KA module.
In all cases, if the switch is set to the closed position, the module accepts
that type of command.
PLC-5 Stations
The PLC-3 processor can read/write to a PLC-5 family processor in
two ways:
as if the PLC-5 processor was a PLC-2 family processor. See “PLC-2
Stations,” page 4-10 for detailed information.
using logical ASCII data type addressing (See chapter 5).
Choosing Between DH or
DH+ Communication
The difference between the communication links is the means of
communication. DH link uses a floating-master function to handle
communication between stations. This function allows a station to access
the DH based on 3 factors:
station’s readiness to transmit a message
message priority
station number
In this way, the floating-master function prevents any single station from
“hogging” the DH link, and it enables the stations to become disabled.
The DH+ protocol uses a token-passing function to handle communication
between stations. The token is constantly passed from station to station
even if no messages are sent. Each station obtains time to send a message.
A station becomes master when it obtains the token. Then it can send a
message to another station. When a station is done communicating, the
token automatically passes to the next higher station number on the link.
DH+ communication is faster than DH communication for configurations
of 16 stations or less. The delay time for link access increases as you
increase the number of stations on the DH+ link.
4-12
Chapter 4
DH and DH+ Communication
Calculating DH and DH+ Communication Times
The time required for the scanner in a local station to send or receive a
message with a scanner in another station on a DH or DH+ link generally
depends on the number of:
stations on the DH+ link
messages transmitted from active stations
bytes of data of all transmitted messages
message requests that are queued ahead of the subject message
Table 4.C lists typical I/O scan times and throughput times for a DH or a
DH+ configuration. The throughput time is the execution time for the
DH or DH+ message. This time starts with setting the enable bit and ends
with setting the done bit in the ladder program of the station sending or
receiving the message.
When calculating these times, the DH/DH+ link had one other station on
the link, and the message instruction was sending 10 words to the second
station. The second station was not transferring any words.
Table 4.C
Throughput Times for a DH or DH+ Configuration in Milliseconds
Number of Active
I/O Channels
Ch
l
Throughput Times
DH
DH+
0
109
66
1
110
67
2
113
67
3
119
67
Important: I/O communication channels can affect the time required to
complete DH+ functions initiated on the same scanner. If any of the
devices in the I/O rack lists are not responding to the scanner (retrys), then
the time to execute some programming terminal DH+ functions, such as
ladder logic searches, will take longer.
4-13
Chapter 4
DH and DH+ Communication
Operating Backup
Configurations on a DH or
DH+ Link
When using a scanner for DH or DH+ communication, you can set up two
types of backup configurations:
two scanners in the same processor chassis for backing up the link
Both scanners are active, and each one is an independent station on the
link. You assign unique station numbers to each scanner. If you want to
send the same message through both scanners, you must program
separate message instructions.
scanners in a backup system
One scanner is in the primary system and one scanner is in the backup
system.
For detailed information on backup systems, refer to the PLC-3 Family
Controller Backup Concepts Manual (publication 1775-6.3.1).
Operating Multiple Links in
One System
By inserting multiple scanners in the same PLC-3 or PLC-3/10 system,
you can operate a single system on more than one link. In this
configuration, each scanner connects to a different link, and each has a
unique station on its associated link. However, all the scanners in the same
system can have either the same or different station numbers.
ATTENTION: If such a PLC-3 station is communicating
through a PLC-2 buffer file on a DH link, and all of the station’s
scanners have the same station number, then all of the scanners
transfer data through the same buffer file. This can cause
unpredictable results if several scanners try to read or write to
the buffer file at the same time (see “Accessing a PLC-3
Processor from a PLC-2 Processor,” page 4-11).
When such a PLC-3 station transmits a command message to a remote DH
or DH+ station, the thumbwheel number specified in the message
instruction determines which scanner actually transmits the command.
4-14
Chapter
5
Addressing DH and DH+ Data Transfers
Chapter Objectives
In chapter 4, we described how you can send a single message command or
a message procedure containing a group of commands. This chapter
explains some general rules for specifying data addresses in message
procedures for communicating over a DH or DH+ link.
Addressing Field
Parameters
To transfer data from one DH or DH+ station to another, you program an
assignment command into the scanner. The assignment command enables
you to copy information from a source to a destination. In this chapter, we
use the following abbreviations to denote the parameters that you can
specify as a source or destination for a data transfer:
Parameter:
Meaning:
bit
number of a particular bit within the addressed word
fileaddr
logical address of a PLC3 file
filesym
symbolic address of a PLC3 file
offset
number of words between the beginning of the file and the
desired word (offset is zero for the first word of a file)
size
number of words that transfer
wordaddr
logical address of a PLC3 word
wordsym
symbolic address of a PLC3 word
You can use a value or an expression for any of the above parameters in an
assignment command.
Interpreting Addresses
When using the above parameters, the scanner interprets values as decimal
(base 10) unless you indicate that they are octal (base 8). Specify an octal
number by starting it with a leading zero. For example, the scanner
interprets 17 as decimal 17, but 017 as octal 17.
Important: An exception to the above rule occurs when addressing a word
in the input or output sections of PLC-3 memory. In these cases, the
scanner normally interprets the word address wordaddr as an octal number,
regardless of leading zeros. To express an input or output word address as
a decimal value, enclose the word address within parentheses and eliminate
leading zeros.
5-1
Chapter 5
Addressing DH and DH+ Data Transfers
In addressing individual bits, parentheses have no effect on the address
interpretation. The scanner interprets the bit address bit as an octal
number if it starts with a leading zero and as a decimal number if it does
not start with a zero.
Some examples are given below:
Addressing Data
Address:
Interpretation (expressed in decimal):
I12:15
input file 12, word 13
I12:15/15
input file 12, word 13, bit 15
I12:015/015
input file 12, word 13, bit 13
I12:015
input file 12, word 13
N43:15
integer file 43, word 15
N43:015
integer file 43, word 13
N043:15
integer file 35, word 15
You reference data by its address in memory. In a message command, you
must precede an address with a dollar sign ($). The dollar sign acts as a
delimiter to tell the scanner that it has encountered a data address
(Figure 5.1).
Figure 5.1
Example Assignment Command Showing Addressing Format
$B45:21 = $I12:33
Destination
Address
Source
Address
Assignment Command
11241
Symbols can also be used to represent data in memory. You must precede
a symbolic address with an at sign (@).
Specifying Addresses
5-2
There are numerous commands that have been defined for operation on the
DH/DH+ data link. You can program the scanner module to transmit a
subset of these commands as listed in Appendix C, Table C.A. The
command sent by the scanner is dependent on the addressing method you
choose in an assignment command when addressing the data in the remote
station.
Chapter 5
Addressing DH and DH+ Data Transfers
The S5 and SR5 scanners offer four different addressing methods for use in
DH and DH+ assignment commands:
PLC-2 Logical Data Addressing
PLC-3 Logical Binary Addressing
Logical ASCII Data Type Addressing
Logical ASCII Word Range Addressing
Although the scanner can transmit and receive any of these addressing
methods, not all remote stations are able to interpret these methods.
Table 5.A indicates which addressing methods are accepted by
other controllers.
Table 5.A
Acceptable Addressing Methods
Accepted by Receiving Station
PLC3
Addressing
PLC2
KA
S5
PLC4
PLC5
PLC5/250
PLC2 Logical Data
X
X
X
X
X
X
PLC3 Logical Binary
--
X
X
--
--
--
Logical ASCII Data Type
--
--
X
--
X
X
Logical ASCII Word Range
--
--
X
--
X
X
Using PLC2 Logical Data
Addressing
A PLC-2 logical data address references a dedicated file in the remote
station. This addressing method simply provides an offset into this PLC-2
data table or PLC-2 compatibility file. The offset is interpreted as octal if a
leading zero is included, otherwise the scanner interprets the number as
decimal.
The receiving station must be able to interpret this form of addressing (see
Table 5.A).
Addressing Words
To address a group of consecutive words in the remote stations memory,
use the following format:
Format:
Example:
offset, size
$047,20
5-3
Chapter 5
Addressing DH and DH+ Data Transfers
You can only address a group of words as the source field in an assignment
command. The destination must be a file that is as large as, or larger than,
the source size plus the offset.
Figure 5.2
Example for Addressing Consecutive PLC2 Words
$ 015 , 4
Number of words to be transferred (decimal)
Delimiter
Word offset from beginning of memory (octal)
Address delimiter
Addressing a single word is similar to addressing a word range only
without specifying a size:
Format:
Example:
offset
$047
Addressing a Bit
To address a specific bit within a word, use the following format:
Format:
Example:
offset/bit
$047/015
Figure 5.3
Example for Addressing Specific Bits in PLC2 Memory
$ 0121 / 010
Bit number 10 (octal)
Bit delimiter
Word offset from beginning of memory (octal)
Address delimiter
5-4
Chapter 5
Addressing DH and DH+ Data Transfers
Using PLC3 Logical Binary
Addressing
When you use a PLC-3 logical binary address, the scanner transmits the
address to the remote station as a six level extended address. This
addressing method is normally reserved for communication between
PLC-3 scanners since the receiving station must be able to interpret this
form of addressing (see Table 5.A). The following rules apply when
specifying a PLC-3 logical binary address:
1.
You must define symbolic addresses to either the word level or the
file level of specification.
2.
A word address can be either a:
logical word address
symbolic address of a word
symbolic file address followed by a colon (:) and an offset
extended address specified to the word level
3.
You must precede a size specification with a word address and a
comma (,).
4.
You must precede an offset specification with a file address and a
colon (:).
5.
You must precede a bit number with a word address and a slash (/).
6.
You can use extended addressing to access the pointer section
of memory.
Addressing a File
To address a file, use either a file address or a file symbol:
Format:
Example:
fileaddr
$N0
filesym
@FILE_A
For assignment commands that copy data from one file to another, both the
source and the destination file must be exactly the same size.
5-5
Chapter 5
Addressing DH and DH+ Data Transfers
Addressing Words
To address a group of consecutive words in memory, use one of the
following formats:
Format:
Example:
wordaddr,size
$N0:47,20
filesym:offset,size
@FILE_A:15,25
wordsym,size
@WORD_1,20
You can only address a group of words as the source field in an assignment
command. The destination must be a file that is as large as, or larger than,
the source range.
Figure 5.4
Example for Addressing Consecutive PLC3 Words
$ N 15 : 0, 20
Address of first word
to be transferred.
Number of words to
be transferred.
Delimiter
11236
Addressing a single word is similar only without specifying a size.
Format:
Example:
wordaddr
$N0:47
filesym:offset
@FILE_A:15
wordsym
@WORD_1
The scanner interprets wordaddr as an octal value if the addressed word is
in an input or output file. Otherwise, it interprets wordaddr as a
decimal value.
You cannot use the pointer data table specifier in an assignment command.
To access words in the pointer section of the PLC-3 data table, you must
use the PLC-3 extended addressing format. For example:
$E3.1.12.0.5.0 (1st word of pointer 5)
$E3.1.12.0.5.1 (2nd word of pointer 5)
5-6
Chapter 5
Addressing DH and DH+ Data Transfers
Refer to the PLC-3 Family Controller Programming Manual (publication
1775-6.4.1) for detailed information on extended addressing.
Addressing a Bit
To address a specific bit within a word, use one of the following formats:
Format:
Example:
wordaddr/bit
$N0:47/015
filesym:offset/bit
@FILE_A:15/8
wordsym/bit
@WORD_1/012
Figure 5.5
Examples for Addressing Specific Bits in PLC3 Memory
@FILE_A:16/8
Bit number 8 (decimal)
Delimiter
Word offset from beginning of file
Delimiter
Symbolic address of file
$B1:5/012
Bit number 12 (octal)
Delimiter
Logical word address
11237
5-7
Chapter 5
Addressing DH and DH+ Data Transfers
Using Logical ASCII
Addressing
The logical ASCII addressing method allows you to communicate with
another device by specifying an address based on the internal memory
structure of the target device. The scanner sends the address as a string of
ASCII characters to the remote station. Upon receiving the string of
ASCII characters, the remote station converts the data into a usable logical
address.
The scanner offers two types of logical ASCII addressing; data type and
word range. In both methods, the scanner transmits the address as an
ASCII string, but the packet of data transmitted by the scanner on the
DH/DH+ link differs.
Data Type
You can use Logical ASCII Data Type addressing to transfer data table
sections without counting the actual words per data table structure. With a
data type packet, the receiving station is notified of the type of data
being sent.
Each station has a common understanding of how the different data types
will be received. It is the responsibility of the sending station to translate
the way it stores a particular data type into this common structure before
transmitting. The receiving station then translates the structure into it’s
method of storage for that particular data type.
To format a logical ASCII data type address, you enclose the address
parameters in double quotes (”):
Format:
Example:
$”address”,size
$”N55:0”,20
Figure 5.6
Example of Logical ASCII Address that Accesses the First Word in File 1
$ ” I1:0 ”
LogicalASCII data type delimiter
Word address in memory
LogicalASCII data type delimiter
Address delimiter
Symbols are allowed inside the double quotes if they are defined in the
remote station.
5-8
Chapter 5
Addressing DH and DH+ Data Transfers
Logical ASCII data type addressing treats data being received and sent
from the floating-point data table section as a special case. The PLC-3
stores floating-point data using DEC-F format and the PLC-5 family store
the same data using IEEE format.
To handle this, whenever you send floating-point data using logical ASCII
data type addressing, the scanner translates the data into IEEE format
before transmitting on the link. Likewise, if floating-point data is received
using logical ASCII data type addressing, the scanner translates the data
from IEEE format into DEC-F format before storing into memory.
Word Range
A logical ASCII word range DH/DH+ packet does not indicate to the
receiving station anything about the data structure. The user assumes
responsibility for possibly sending unlike data types to the remote station.
For example, integer data to a BCD file.
The sending station simply sends the data from the data table address given
and the receiving station stores that same data at the indicated address. No
error checking is done for compatible data table areas.
To format a logical ASCII word range address, you enclose the address
parameters in single quotes (’):
Format:
Example:
$’address’,size
$’N55:0’,15
Symbols are allowed inside the single quotes if they are defined in the
remote station.
Figure 5.7
Example of Logical ASCII Address that Accesses the 17th Word in File 4
$ ’ N4:17 ’
LogicalASCII word range delimiter
Word address in memory
LogicalASCII word range delimiter
Address delimiter
5-9
Chapter 5
Addressing DH and DH+ Data Transfers
Addressing Stations on a
Local Link
Figure 5.8 shows the format for addressing data at remote stations on a
local link. The pound sign (#) specifies a remote station on a DH or DH+
link.
Figure 5.8
Example for Addressing a Word in a Remote Station on a Local DH/DH+
Link
# H 020 $ B 15:9
Word address at remote station
Address delimiter
Remote station number 20 (octal)
Port indentification for data highway port
Remote station delimiter
# H 020 @ WORD_9
Symbolic word address defined at remote station
Remote station number 20 (octal)
Port indentifier for data highway port
Remote station delimiter
15420
Remote station addresses have the following restrictions:
You can only use a remote address with the single equals sign (=) type
of assignment command.
In the assignment command, either the source or the destination, but not
both, can be a remote address.
A remote address can contain an embedded expression, but you cannot
embed a remote address in an expression.
You can substitute symbols or logical addresses for the remote
station number.
For example, the remote station being addressed by #H($N1:0)$B15:9
will be the integer value contained in N1:0.
5-10
Chapter 5
Addressing DH and DH+ Data Transfers
Addressing Stations on a
Remote Link
In DH+ protocol, you can use the format shown in Figure 5.9 to address a
remote station that is located across a bridge on another link.
If you have the scanner configured for DH protocol, using this format
causes a communication error to occur.
Figure 5.9
Example for Addressing a Remote Station Located on a Remote DH+
Link
# H 5 : 13 : 050 . 1 $ B15:9
Word address at remote station
Address delimiter
User number (015)
if 0 you can drop the period and user number
Remote station number (0077 octal)
must enter even if 0
Link delimiter
Link number (032767 decimal)
If 0 you can leave out but still enter in colon delimitors
Bridge delimiter
Bridge number (0077 octal)
If 0 you can leave out but still enter colon delimitors
Remote link type
Specify an H in this field. (D and 0 are acceptable in rare cases when the remote
device requires other than 2 bytes of destination and source address. The D
would provide 1 byte and the 0 provides 6 bytes).
Remote station delimiter
For data locations at remote stations, a pound sign (#), followed by the
remote link type (H for DH or DH+ communication) and the remote
station number, precede the data address (Figure 5.10).
5-11
Chapter 5
Addressing DH and DH+ Data Transfers
Figure 5.10
Example Assignment Command that Addresses a Remote Station
#H024 $B45:21 = $I12:33
Source Address
Address Delimiter
Assignment Command
Destination Address
Address Delimiter
Remote Station Number (octal)
Data Highway Port Identifier
Remote Station Delimiter
11242
Assignment Command
You can use the assignment command to copy data from a source location
to a destination location (Table 6.D). Source types include:
direct values
procedural user symbols
interprocedural user symbols
logical addresses
local symbolic addresses
global symbolic addresses
expressions
Destination types include:
procedural user symbols (except when the source is remote)
interprocedural user symbols (except when the source is remote)
logical addresses
local symbolic addresses
global symbolic addresses
You can use any source type listed above with any destination. If the
destination is a user symbol, the scanner checks to see if it has previously
been defined. If the user symbol was not previously defined, a new
symbol is generated.
Important: You cannot transfer data from another station and place it into
a user symbol defined at the local controller.
5-12
Chapter 5
Addressing DH and DH+ Data Transfers
Formatting an Assignment Command
The equal sign (=) is the assignment command. The destination is on the
left of the equal sign, and the source is on the right. When the scanner
executes an assignment command, it assigns or copies the source value to
the destination. For example:
$I12:024 = US_5
The scanner copies the value of user symbol US_5 into word 24 (octal) of
input file 12 (see “Using Symbols,” page 6-4).
Available Modifiers
You can add several modifiers to the assignment command to change the:
scope of the assignment
priority level of a DH message
type of command message transmitted
Scope of the Assignment
If the destination for an assignment command is a user symbol, then you
can use a double-equal sign (==) in place of the single equal sign to specify
that the user symbol be interprocedural in scope. The single equal sign
defines a procedural user symbol. For example:
US_2 == 6
The scanner defines US_2 to an interprocedural user symbol and assigns it
the value 6 (see “Using Symbols,” page 6-4).
Message Priority (DH only)
If you want to give priority to a DH message, you can use the less-than
sign with the equal sign (<=). Without the less-than sign, the assignment
command generates a normal message. For example:
#H027$I15:4 <= $I12:24
The scanner transmits a priority message to station 27 (octal).
You can use the priority modifier with either type of assignment (= or ==).
Important: For DH communication, stations with high priority messages
are given priority over stations with no-priority messages throughout the
command/reply cycle. For this reason, you should only give a
high-priority designation to a command when special handling of specific
data is required. Using an excessive number of high priority commands
defeats the purpose of this feature and could delay or inhibit the
transmission of no-priority messages.
5-13
Chapter 5
Addressing DH and DH+ Data Transfers
Important: The scanner ignores the message priority modifier for DH+
messages.
Command Message Type
Command messages can be protected or unprotected:
Protected commands can access only specified areas of data table
memory at a PLC-2 station. You need to send a protected write
command only if a switch at the remote PLC-2 station prohibits other
stations from sending unprotected write commands.
Unprotected commands can access any area of the data table.
For more information, see chapter 4.
By default, the assignment command generates protected command
messages. To generate an unprotected command message, enter a space
followed by a U after the assignment command statement.
For example:
#H027$0121 = 17407
The scanner generates a protected write command to write the value
17407 to word 121 of DH station 27.
#H027$0121 = 17407 U
The scanner generates an unprotected write command to write the
value 17407 into word 121 of DH station 27.
You can disable the transmission of unprotected commands through LIST
options (see chapter 2).
Identifying Remote Stations
Remote stations in an assignment command can be identified with an
integer value (Figure 5.10), a symbol, a PLC-3 data table address, or
system symbol.
For example:
5-14
#H(STANUM)$N0:0 = $N0:0
; STANUM = 19
#H($N1:0)$N0:0 = $N0:0
; $N1:0 = 19
#H(@SMITH)$N0:0 = $N0:0
; @SMITH is equated to $N1:0
Chapter 5
Addressing DH and DH+ Data Transfers
Programming Examples of
Assignment Commands
This section gives examples of assignment commands using the four
available addressing methods. Often, the choice of addressing method and
the structure of the data table section which is being addressed, determines
what data is actually sent.
Timers, counters, high-order integers, floating point, and pointers are all
stored in the PLC-3 memory as multiple words. Each timer and counter
contained in the PLC-3 uses 3 consecutive words; one for the control bits,
one for the preset value, and one for the accumulated value. Timers and
counters are stored in the following order:
CTL PRE ACC
The PLC-3 stores high-order integers and floating point numbers as two
words. Pointers consume three words each in PLC-3 memory.
Table 5.B
PLC2 Logical Data Addressing
Data Addressing
Description
#H021$040 = $B3
write data from entire binary file 3 to remote station
21 beginning at word 40 octal.
#H021$040 = $B3:5,20
write the twenty words beginning at binary file 3,
word 5 to remote station 21, beginning at word 40
octal.
#H021$40 = $B3:5
write binary file 3, word 5, to remote station 21 word
40 decimal.
#H021$040/5 = $B3:5/13
write binary file 3, word 5, bit 13, to remote station
21 word 40 octal, bit 5.
#H021$040 <= $B3:5
as a priority message, write binary file 3, word 5 to
remote station 21 word 40 octal. If the scanner is
configured for DH+, the priority modifier is ignored.
#H021$040 = $B3:5 U
send an unprotected write of binary file 3, word 5, to
remote station 21 word 40 octal.
5-15
Chapter 5
Addressing DH and DH+ Data Transfers
Table 5.C
PLC3 Logical Binary Addressing
Binary Addressing
Description
#H02$F0:0 = $F0:0,6
write 6 contiguous words beginning with floating
point file 0, word 0 to remote station 2 floating point
section file 0 word 0. A total of three complete
floating point words (2 words each) are being
transferred.
$D0:0 = #H054$E0.0.0.14
read the year from the system clock of remote
station 45 and store the data in decimal file 0, word
0. Writes to nondata table addresses are not
allowed.
#H014$T0:5 = $T4,2
write two words beginning with timer four to remote
station 14 timer 5. In this example, the data in
$TCTL:4 and $TPRE:4 is written to $TCTL:5 and
$TPRE:5 respectively in the remote station.
#H046$N0:0 = $N4:1
write integer file 4, word 1 into remote station 46's
integer file 0, word 0.
#H055$N1 = $N0
the entire integer file 0 is written into integer file 1 of
remote station 55. The file sizes must be identical.
#H02$H0:0 = $H0:0,6
high order integers are treated as 32 bits or 2
words. This example writes 6 complete high order
integers to remote station 2.
Table 5.D
Logical ASCII Data Type Addressing
5-16
Data Type Addressing
Description
$N0:10 =
#H003$”N55:0”,100
read 100 words from remote station 3 beginning
with integer file 55, word 0 and store the data in
integer file 0, beginning with word 10.
$D0:0 = #H055$”N0:0”
read integer file 0, word 0 from remote station 55
and store data in decimal file 0, word 0.
#H020$”B10:10” = 15
write a decimal value of 15 into binary file 10, word
10 of remote station 20.
#H014$”T5” = $T4,4
write the contents of four complete timers (three
words each) beginning with timer 4 into remote
station 14 beginning with timer 5.
#H02$”F0:0” = $F0:0,6
write the contents of 6 complete floating point
numbers (two words each) into remote station 2
beginning with floating point number 0.
Chapter 5
Addressing DH and DH+ Data Transfers
Table 5.E
Logical ASCII Word Range Addressing
Word Range Addressing
Description
#H024$’D1:0’ = $D1:0,2
write two words beginning with decimal file 1, word
0 into remote station 24's decimal file 1, word 0.
#H040$’@PUNCH’ = $A1:0
write the data stored at ascii file 1, word 0 into
remote station 40 which will store the data at the
address defined by symbolic address @PUNCH.
This symbol must be created and defined in the
remote station.
#H014$’T0:5’ = $T4,6
write 6 contiguous words beginning with $TCTL:4,
into remote station 14 beginning with timer five. In
this example, timers 4 and 5 (3 words each) would
be transferred complete.
#H014$’C5’ = $C4,5
write 5 contiguous words beginning with $CCTL:4
into remote station 14 beginning with counter 5. In
this example, $CCTL:4, $CPRE:4, $CACC:4,
$CCTL:5, and $CPRE:5 would be transferred into
$CCTL:5, $CPRE:5, $CACC:5, $CCTL:6, and
$CPRE:6 respectively.
5-17
Chapter
6
Programming DH and DH+ Message
Procedures
Chapter Objectives
This chapter explains how to create, edit, and use the message instruction
to operate the DH and DH+ communication channel on the scanner. This
chapter helps you learn how to:
enter a message instruction into the ladder program
program message command, functions, and procedures
add comments to a message procedure
program message procedures to monitor and recover from errors that
occur during message command execution
Message Instruction
Considerations
You do not always have to create a message procedure. If you want to
execute just a single assignment command that is not longer than 120
characters, you can enter that command in the message-instruction block
(Table 6.A). If you want to execute more than one assignment command,
you must create a message procedure to contain those commands.
The execution of a single assignment command takes place once the
scanner receives the message instruction from the CPU. However, when a
message instruction contains a message procedure, the scanner must first
store the symbols within your procedure into system memory and begin
retrieving the procedure lines from system memory. Allow for this
initialization time when initiating procedures. After this initial time, the
commands within a procedure execute as fast as single commands within a
message instruction.
6-1
Chapter 6
Programming DH and DH+
Message Procedures
Editing the Message
Instruction
The general steps for editing a DH or DH+ message procedure are:
1.
Create and edit the ladder program containing message instructions
that control execution of the message procedure.
2.
Allocate memory to the necessary data files.
3.
Create and edit the message procedure.
You can perform these steps through your programming terminal. Refer to
its user’s manual for detailed information on creating and editing the
ladder program.
You can also perform the third step through an RS-232-C data terminal
connected to an RS-232-C channel on a Peripheral Communication
Module (cat. no. 1775-GA).
Table 6.A gives an example of how to edit the message instruction in the
ladder program. For more details on ladder-program editing, refer to the
user’s manual for your programming device.
Table 6.A
Entering the Message Instruction into the Ladder Program
Prompt (if any)
Action
Start editing session.
Insert a new rung.
Enter the bit that conditions the message rung.
Enter the message instruction.
ENTER FILE
ADDRESS
Enter the address of the file where the message resides in
memory. This file should be binary.
ENTER SYSTEM
ADDRESS OR
SYMBOL
Enter the channel designation for the scanner:
For example, E2.3.4:
• E2 is the module status
• 3 is the scanner module type
• 4 is the thumbwheel number
ENTER MESSAGE
TYPE
Enter the message type. This is always 1.
Enter a single assignment command or the name of a message
procedure. In this case, the message procedure name is PROC1.
End the editing session.
6-2
Chapter 6
Programming DH and DH+
Message Procedures
Figure 6.1
Examples of Message Instructions
Reading word 5 of binary file 3 at station 045 into word 17 of integer file 4.
MSG
I0012
MESSAGE TYPE
CTL=FB200:0000=000
CH:E2.3.1
$N4:17=#H045$B3:5
01
Destination
(local)
1
STAT
EN
12
STAT
DN
15
STAT
ER
13
Source
(remote)
Execute procedure @PROC_A
MSG
I0012
MESSAGE TYPE
CTL=FB200:0000=000
CH:E2.3.1
@PROC_A
01
1
STAT
EN
12
STAT
DN
15
STAT
ER
13
Allocating Memory
Before the scanner can transfer data to or from any file in memory, the file
must exist and be large enough to accommodate the data transfer. You can
create and allocate a file using memory management through your
programming terminal. Refer to the user’s manual for your programming
terminal for detailed information.
6-3
Chapter 6
Programming DH and DH+
Message Procedures
Editing Message Procedures
Table 6.B shows how to edit a message procedure through an RS-232-C
data terminal connected to a 1775-GA module.
Table 6.B
Editing a Message Procedure Through an RS232C Data Terminal
Prompt (if any)
Action
Keystrokes
GA1>
Enter the edit mode and create the message
procedure name. The GA module creates the
symbol definition for the message procedure
name.
EDIT/H @PROC1 [RET]
<EOB>
*
Enter the insert mode for editing.
I [RET]
Enter the message procedure commands. You
must use an EXIT or STOP command to end
each procedure.
(other commands)
#H022$B0:5=$N3:1 [RET]
$B0:6=$N3:1 [RET]
*2 [RET]
EXIT [RET]
Exit the insert mode.
[RET]
Exit from the editing mode.
E[RET]
GA1>
Using Symbols
You can also use symbols to represent data and data addresses in
message commands.
A symbol can consist of numeric digits, alphabetic characters, and the
underscore (_). The scanner does not allow any other special characters.
Important: The first character in a symbol must be a letter (A - Z).
The scanner recognizes both upper-case and lower-case letters in a
symbol as different characters
For example, ASYMBOL and Asymbol are two different symbols.
A symbol can be any length, but it must be unique in its first
eight characters
For example, the scanner can distinguish SYMBOL_A and
SYMBOL_B in a message procedure, but NEW_SYMBOL_A and
NEW_SYMBOL_B are not.
Important: The scanner does not flag indistinguishable symbols as
programming errors. It treats similar symbols as equivalents.
6-4
Chapter 6
Programming DH and DH+
Message Procedures
You cannot use certain words and character combinations as symbols
because they are reserved for special uses in message procedures. The
reserved words are:
CREATE
DELETE
ERROR
EXIT
GOTO
IF
ON_ERROR
STOP
PROT
UNPRO
You also cannot use any abbreviated form of the above words. For
example, you cannot use the single letter C as a symbol because it is an
abbreviation of the word CREATE. Similarly, PRO is an invalid symbol.
The two types of symbols are (Figure 6.2):
user symbols
system symbols
Figure 6.2
Types of Symbols
User Symbol
Generate this symbolic
value through the
assignment command.
Interprocedural
Applies to the procedure
in which it is generated
plus any other procedure
nested together with that
procedure.
System Symbol
Generate this symbol
with the Edit command
(for a procedure name)
or a Create command
(for a symbolic address).
Symbol
Procedural
Applies only to the
procedure in which it is
generated.
Procedure Name
Applies to a single
procedure or other
procedures nested
together within that
procedure.
Symbolic Address
Can be used anywhere
in place of a logical
address.
Global
Applies to any context.
Local
Applies only to the
context in which the
symbol is generated.
12161
6-5
Chapter 6
Programming DH and DH+
Message Procedures
Using User Symbols
A user symbol represents a numeric value. You can generate a user
symbol and assign a value to it by means of the assignment command (see
chapter 5).
Type
Description
procedural
The scanner recognizes procedural user symbols only in the procedure that
you generate it in.
interprocedural
The scanner recognizes interprocedural user symbols in the procedure that
you generate it in and any other procedure nested within that procedure.
User symbols can contain data that is up to 32 bits long. If the high-order
bits are insignificant (that is, if they can be truncated without changing the
value of the data), then the scanner can store the contents of the user
symbol in a data field that is less than 32 bits long. Attempting to put a
data value into a field that is too small, causes the scanner to generate error
code 189 (see appendix B).
Using System Symbols
Use a system symbol as either a procedure name or a symbolic address.
You must name a system symbol following the general rules given in
“Using Symbols,” page 6-4. The character @ delimits a system symbol
and distinguishes it from a user symbols.
Symbol Type Description
procedure
names
A procedure name is a way of referring to a message procedure. You assign a
procedure name at the time you generate or edit the message procedure.
One procedure can execute a second procedure simply by stating the name of
that second procedure. This allows for nesting of procedures up to 3 levels deep.
symbolic
addresses
A symbolic address is another way of representing the logical address of data.
You can generate a symbolic address by using the CREATE command. You can
use a symbolic address for a logical address anywhere in a message procedure.
The system symbols area of memory stores all symbolic addresses.
scope of
system
symbols
System symbols can be either local or global in scope. The scanner recognizes
a global system symbol in any context. It recognizes a local system symbol only
in the operating context that the system symbol is created in. For detailed
information on context, refer to the PLC3 Family Controller Programming Manual
(publication 17756.4.1).
At the time you generate the system symbol, you specify it to be local or global.
If you do not specify the scope of the system symbol, it defaults to local.
Important: Do not confuse the terms local and global symbols with local and
remote stations. Both local and global symbols have meaning only at the station
where you generate them.
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Message Procedures
Using Expressions
Expressions use operators to combine two or more numeric values into a
single value. Table 6.C lists the operators that you can use in an
expression. We list these operators from highest priority (1) to lowest
priority (10). The result of an expression depends on the order the scanner
executes the operations. The order of execution depends on the type of
operator and on left-to-right placement within the expression.
The result of an expression is a 32-bit value. If the high-order bits are not
significant (that is, if they can be truncated without changing the value of
the expression), then a data field that is less than 32 bits long can store the
value. Attempting to put a value into a field that is too small results in
error code 189 (see appendix B).
Table 6.C
Expression Operators
Operator
Order of Execution
Description
/
1
bit operator
.NOT.
1
logical complement
~ or .BNOT.
1
bitwise 32bit complement
*
2
multiplication of 32 bits
%
2
division of 32 bits
+
3
addition of 32 bits
-
3
subtraction of 32 bits
<<
4
left arithmetic shift
>>
4
right arithmetic shift
& or .BAND.
5
bitwise 32bit AND
^ or .BXOR.
6
bitwise 32bit EXCLUSIVE OR
| or .BOR.
7
bitwise 32bit OR
.EQ.
8
compare equals
.GT.
8
compare greater than
.GE.
8
compare greater or equal
.LT.
8
compare less than
.LE.
8
compare less or equal
.NE.
8
compare not equal
.AND.
9
logical AND
.OR.
10
logical OR
You can nest expressions within other expressions by enclosing the inner
expression within parentheses.
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Message Procedures
For example, the following command stores the value 12 in word 45 of
binary file 67.
$B67:45 = 6+3*2
This occurs because the scanner multiplies before it adds.
If an expression contains several operators within the same order of
execution, the scanner executes those operators in the left-to-right order in
which they appear within the expression.
You can enter extra sets of parentheses to change the order of execution.
In such cases, the scanner evaluates the expression within the inner-most
set of parentheses first.
For example, the following command stores the value 2 in word 45 of
binary file 67 (% is the operator for division):
$B67:45 = 36%((6+3)*2)
You can use expressions anywhere for direct numeric values in a message
procedure, including within an address field.
For example, in the following statement, the expression (WORD+3)
specifies the address of a word within binary file 67:
$B67:(WORD+3) = 5
The parentheses are necessary to indicate that +3 is part of the word
address in this case.
Interpreting Expressions
Within an expression, the scanner always interprets direct numeric values
as decimal (base 10) numbers unless you indicate that they are octal (base
8). Specify an octal value by starting the number with a leading zero.
For example, the scanner interprets 17 in an expression as decimal 17, but
it interprets 017 as an octal 17 (or decimal 15).
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Message Procedures
Bit Operator
The bit operator allows you to address a specific bit of a value stored under
a user symbol. For example:
$l12:24/7 = US_13/4
This statement puts the value (0 or 1) of bit number 4 of user symbol
US_13 into input file 12, word 24, bit 7.
The bit address itself can also be a user symbol or an expression. For
example:
$l12:24/7 = US_3/(4+US_1)
The expression (4+US_1) specifies a particular bit within user symbol
US_3.
The value appearing after the bit operator must be within the range of
values allowed for bit addresses. Since user symbols are 32-bit values, a
bit address for a user symbol must be in the range of 0 to 31 (decimal). Bit
addresses for data table words must fall in the range of 0 to 15 (decimal).
Logical Operators
The logical operations are NOT, AND, and OR. These operations
construct logically true or false conditions. You generally use them in
decision statements such as the IF command.
The result of a logical complement is 1 (true) if the expression following
the .NOT. is a value of 0. Otherwise, the result is 0 (false).
For example:
$l12:24 = .NOT.SYMBOL_A
If SYMBOL_A is:
Then the scanner stores this value in input file 12 word 24:
0
1
not 0
0
The result of a logical AND is 1 (true) if the expression preceding the
.AND. and the expression following the .AND. are both non-zero.
Otherwise, the result is 0 (false).
The result of logical OR is 1 (true) if either the expression preceding the
.OR. is non-zero, the expression following the .OR. is non-zero, or both
expressions are non-zero. Otherwise, the result is 0 (false).
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Message Procedures
Bitwise Operators
Bitwise operators manipulate the individual bits in a 32-bit operand.
The bitwise 32-bit complement (.BNOT.) inverts the state of each bit in the
32-bit expression. That is, bits set to 1 invert to 0, and bits set to 0 are
invert to 1.
The bitwise 32-bit AND (.BAND.) forms a bit-by-bit logical AND of two
32-bit operands. No carry occurs from one bit position to the next within
the operand. For example:
A contains the bit pattern:
10101010010011110010101010101011
B contains the bit pattern:
01110101011100100010101110001010
Then the assignment C=A.BAND.B yields
C contains the bit pattern:
00100000010000100010101010001010
The bitwise 32-bit EXCLUSIVE OR (.BXOR.) forms a bit-by-bit logical
XOR of two 32-bit operands. No carry occurs from one bit position to the
next within the operand.
The bitwise 32-bit OR (.BOR.) forms the bit-by-bit logical OR of two
32-bit operands. No carry occurs from one bit position to the next within
the operand.
Arithmetic Operators
The arithmetic operations are addition, subtraction, multiplication, and
division. These are binary (not BCD) operations that produce 32-bit
signed integer results.
You should assign a result from these arithmetic operations to a 32-bit
destination. However, you can assign the result to a 16-bit destination if
the result is small enough in absolute value (less than 65,535) to fit into 16
bits. If you assign the result to a 16-bit word and the result is too large to
fit into 16 bits, then an error code of 215 results.
The scanner does not indicate overflow or underflow conditions with
arithmetic operations.
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Message Procedures
Shift Operators
The scanner supports the following shift operators:
If you see:
It means the bit shifts:
<<
left
>>
right
The shift operators shift binary values a specified number of bit positions
to the left or right.
When a left arithmetic shift (<<) executes, zeros shift into the rightmost
bits of the expression. The leftmost bits shift out of the expression and are
lost, thus possibly changing the sign bit. The left bit shift operates in this
manner whether operating on 16 or 32 bit values.
PUMP = (PUMP << 1)
PUMP Value:
Bit Pattern (32bits):
Decimal Value:
Before operation
100...00000101
-2147483643
After operation
000...00001010
10
In a similar manner, when a right bit shift (>>) is executed on a 16 bit
value in the data table, zeros shift into the leftmost bits of the expression.
The rightmost bits shift out of the expression and are lost. As shown in
this example, the sign can change when using the shift operators on 16-bit
values.
$N0:1 = ($N0:1 >> 1)
$N0:1 Value:
Bit Pattern (16bits):
Decimal Value:
Before operation
10000011 00000000
-32000
After operation
01000001 10000000
16768
However, the right bit shift works differently when the operation is
performed on 32 bit values such as are created with user symbols, and also
values in the high order integer data table section. In this case, the leftmost
bit of the expression does not change.
If the leftmost bit is a:
Then:
1
a 1 is shifted in from the left.
0
a 0 is shifted in from the left.
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Message Procedures
Since the leftmost bit of an expression is the sign bit, this means that the
right bit shift on a 32-bit value does not change the sign of the numeric
value. The rightmost bits still shift out of the value and are lost as shown
in the following examples:
GRINDER = (GRINDER >> 1)
GRINDER Value:
Bit Pattern (32bits):
Decimal Value:
Before operation
100...00000101
-2147483643
After operation
110...00000010
-1073741822
$H0:1 = ($H0:1 >> 1)
$H0:1 Value:
Bit Pattern (32bits):
Decimal Value:
Before operation
010...00000101
1073741829
After operation
001...00000010
536870914
Comparison Operators
Comparison operators result in a value of 1 if the comparison is true and 0
(zero) if the comparison is false. For example:
$I12:24 = ($CACC:1.GE.$CACC:2)
6-12
If the accumulated value of counter 1
is:
Then the scanner stores this value in
input file 12 word 24:
greater than or equal to the accumulated
value of counter 2
1
less than the accumulated value of
counter 2
0
Chapter 6
Programming DH and DH+
Message Procedures
Message Procedure
Commands
The scanner has its own command language that you can use in
programming message procedures. Table 6.D summarizes these
commands.
Table 6.D
Message Procedure Commands
Command
Format and Explanation
(assignment)
destination = source
See
page:
Assign a numeric value to a user symbol or copy data from the source to the
destination (see chapter 5).
CREATE
C @system symbol$logical address
614
Create a symbolic address and equate it to a logical address.
DELETE
D @system symbol
614
Delete a symbolic address or an entire message procedure from memory.
(execute)
@system symbol
615
Execute the named message procedure.
EXIT
E
615
Terminate execution of the current message procedure.
GOTO
G label
615
Continue executing the current procedure from the point specified by the label.
IF
I expression embedded command
616
Execute the embedded command only if the specified expression is true.
ON_ERROR
O embedded command
616
Execute the embedded command only if an error occurs after this statement in
the procedure.
STOP
S
617
Terminate execution of the message (MSG) instruction in the ladder program.
You can abbreviate each command to the letters shown in the format and
Explanation column of Table 6.D. We recommend that you use the
command abbreviations because they:
make the commands easier to program
save memory space
reduce execution time
You can insert spaces in command lines to make the message procedure
easier to read. However, you should keep spaces to a minimum, because
they use memory space and slow execution of the message procedure.
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Chapter 6
Programming DH and DH+
Message Procedures
CREATE Command
The CREATE command generates a symbolic address and assigns it to a
logical address. To create a local symbolic address, use the CREATE
command by itself (the default modifier /LOCAL is optional). To create a
global symbolic address, use the modifier /GLOBAL after the CREATE
command. A procedure executing in any context can use any global
symbolic address, whereas local symbolic addresses are recognized only
by procedures executing in the same context. In either case, the symbol
has meaning only at the station where it is created.
You can abbreviate the modifier /GLOBAL to /G and /LOCAL to /L.
For example:
C/G @TOTAL $E0.0.0.7
The scanner creates the global system symbol TOTAL to represent the
logical address E0.0.0.7.
Do not confuse this CREATE command for generating symbolic addresses
with the CREATE command for allocating file space in PLC-3
programming.
DELETE Command
Use the DELETE command to:
delete message procedures from memory
delete symbolic addresses
delete interprocedural user symbols
Using the DELETE command on a:
Deletes the:
procedure name
name and erases the named procedure from
memory.
symbolic address or user symbol
symbol, but the data stored under that symbol
remains intact.
To delete a local symbol, a local procedure or a procedural user symbol,
use the DELETE command by itself (the modifier /LOCAL is optional).
To delete a global symbol, a global procedure, or an interprocedural user
symbol, use the modifier /GLOBAL after the DELETE command.
You can abbreviate the modifier /GLOBAL to /G and /LOCAL to /L.
For example:
D/G @PARTS_PG
The scanner deletes the global procedure PARTS_PG from
PLC-3 memory.
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Message Procedures
Execute Command
To execute a message procedure, enter the delimiter @ followed by the
procedure’s name. For example:
@FIRST_PROC
The scanner executes the procedure FIRST_PROC.
You can use procedure names anywhere that commands are used. This
way one procedure can execute (call) another procedure. This allows for
nesting of procedures. However, you cannot nest more than 3 layers deep.
EXIT Command
The EXIT command terminates execution of the current message
procedure. If another procedure calls (executes) the current procedure, the
EXIT command returns control to the calling procedure at the line
following the execute statement.
The format for the EXIT command is the single letter E without any
modifiers or parameters.
Each main procedure and nested procedure must end with either an EXIT
command or a STOP command. The EXIT command is preferred because
the STOP command results in error 179 (see appendix B).
GOTO Command
The commands in a message procedure normally execute sequentially.
The GOTO command can change the order of execution.
The parameter for a GOTO command is a label. Labels are signposts, or
tags, that mark a location within the message procedure.
To generate a label, enter it on any one of the lines in a message procedure.
For example:
LABEL_A:
Nothing else can appear on the same line with the label. The label itself
must conform to the same rules of construction as user symbols do.
Important: The trailing colon (:) is required when you first generate the
label, but do not use the colon any other time you refer to the label.
When a GOTO command executes, execution of the message procedure
resumes with the first command after the label specified in the GOTO
command. You cannot use the GOTO command to jump from one
procedure to another, even if the procedures are nested.
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Message Procedures
IF Command
The IF command makes logical decisions in the message procedure. The
first parameter of the IF command is an expression (see “Using
Expressions,” page 6-7). You must enclose the entire expression in
parentheses. Use multiple operators for complex or nested expressions.
The second element in the IF command is an embedded command. If the
value of the expression is true (1), the embedded command executes. If
the value of the expression is false (0), the embedded command does not
execute. The embedded command can be any available command except
another IF or an ON_ERROR command.
Figure 6.3 shows the combination of a label, a GOTO command, and an IF
command to construct a simple loop that assigns the integers 0 through 7 to
successive words in binary file 50.
Figure 6.3
Example of Looping
(other commands)
NUM = 0
LOOP:
$B50:(NUM) = NUM
NUM = (NUM + 1)
IF (NUM .LE. 7) GOTO LOOP
(other commands)
ON_ERROR Command
The ON_ERROR command specifies what action should be taken if an
error occurs during execution of the message procedure. The ON_ERROR
command does not execute sequentially in the procedure; it executes only
when an error occurs.
The ON_ERROR command contains an embedded command and applies
to all other commands between itself and the next ON_ERROR command.
For example:
command line 1
command line 2
ON_ERROR GOTO RECOVER
command line 3
command line 4
ON_ERROR ERR_CODE = $B2:16
command line 5
In these command lines, the first ON_ERROR command applies to
command lines 3 and 4, while the second ON_ERROR command applies
to command line 5.
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Message Procedures
If an error occurs in a command line that is not associate with an
ON_ERROR command, the procedure stops executing. See “Recovery
from Erros,” page 7-1.
Refer to Appendix B for a listing of the error conditions.
STOP Command
The STOP command terminates execution of the message instruction in the
ladder program. This means that the STOP command stops execution of
the current procedure and all procedures nested together with the
current one.
The format of the STOP command is the single letter S without any
modifiers or parameters.
Each main procedure and nested procedure must end with either an EXIT
or a STOP command. The STOP command is a extreme means of
terminating a message procedure, so you should only use it when no other
action is possible. The normal means of terminating a procedure is the
EXIT command. The STOP command generates error code 179 (see
Appendix B).
Using Functions
In addition to containing commands and nested procedures, a message
procedure can also contain functions. You can use the following functions
anywhere expressions are used (Figure 6.4):
TO_BCD
FROM_BCD
The TO_BCD and FROM_BCD perform opposite conversion functions.
Figure 6.4
Example Command Lines Using the TO_BCD and FROM_BCD Functions
$D:12 = TO_BCD (27)
COUNT = FROM_BCD ($D:12)
Function Parameter
Function
Assignment Command
Destination of
Resulting Value
11245
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Chapter 6
Programming DH and DH+
Message Procedures
You must enclose the parameter of the function in parentheses. The
parameter can be a/an:
direct numeric value (either decimal or octal)
expression
user symbol
logical address
symbolic address
TO_BCD Function
The TO_BCD function converts its parameter into a binary coded decimal
value that is 32 bits long. For example, the TO_BCD function in
Figure 6.4 stores the number 27 in binary-coded-decimal format in word
12 of the decimal section of memory. After this function executes, word
12 contains the following bit pattern:
0000 0000 0010 0111
FROM_BCD Function
The FROM_BCD function converts its parameter from
binary-coded-decimal format to binary format. The resulting value is 32
bits long. For example, the FROM_BCD function in Figure 6.4 converts
the contents of decimal word 12 from binary coded decimal to a regular
decimal value of 27. After this function executes, the FROM_BCD
function stores the following bit pattern in user symbol COUNT:
0000 0000 0000 0000 0000 0000 0001 1011
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Chapter 6
Programming DH and DH+
Message Procedures
Adding Comments to Your
Message Procedure
You can add comments to any command line in a message procedure. To
do this, enter a semicolon (;) after the command. Then enter your
comment after the semicolon (Figure 6.5).
Figure 6.5
Format for Adding Comments to Command Lines
COUNT = 0
; INITIALIZE COUNTER
Comment
Comment Delimiter
Command
11246
Anything that appears between a semicolon and the end of the command
line is a comment. Comments can be any length. The end of the command
line, and therefore the end of your comment, is delimited by the
carriage-return and line-feed pair of characters.
Programming Examples for
a Message Procedure
Figure 6.6 and Figure 6.7 provide examples of DH or DH+ message
procedures that monitor the state of a status bit in a remote station.
Figure 6.6
Example Message Procedure that Executes Read and Write Commands
over a DH or DH+
Procedure - @DATA
A = 10
B = $N0:0
IF ($10:012/017) $D2:0 = #H011$D6:0
IF ($10:012/016) #H011$D6:1 = $D2:1
IF (A .EQ. B) GOTO LABEL
EXIT
LABEL:
$D7 = #H011$D3
#H011$N3:5 = $N2:4,10
;procedural user symbol
;read word D6:0 from station 11 into word D2:0
;write word D2:1 into word D6:1 of station 11
;note that the destination file must be ≥ the source
file
;write 10 words starting at word N2:4 into
;station 11 starting at word N3:5
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Chapter 6
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Message Procedures
Procedure -- @REM_TURNON
Figure 6.7
Example Message Procedure that Monitors the State of a Bit in a Remote
Station and Records Any Error Condition
;This procedure monitors the state of a bit in a remote station.
;When that bit goes true, the scanner turns on a bit locally for
;either 300 seconds or until the remote bit goes false.
ON_ERROR @LOG_ERROR
;log errors and time of day
A == 0
;initialize error pointer (interprocedural user symbol)
CREATE @TIM_START $B0:0
;timer start word (local system symbol)
CREATE @TIM_CTL $TCTL:1
;timer control word
CREATE @TIM_PRE $TPRE:1
;timer preset word
T_ON_BIT = 0
;timer on bit (procedural user symbol)
T_DONE_BIT = 017
;timer done bit
CREATE @PROCESS $N3:7
;process word
P_ON_BIT = 5
;process on bit
ON = 1
OFF = 0
LOOP1:
;check remote bit in loop
$B0:0/1 = #H023$B5:3/2
;fetch and save remote bit
IF ($B0:0/1 .EQ. OFF) GOTO LOOP1
@TIM_PRE = 300
;set timer for 300 sec
@TIM_START/T_ON_BIT = ON
;turn timer rung condition on
@PROCESS/P_ON_BIT = ON
;turn process on
LOOP2:
;check timer and remote bit in loop
$B0:0/1 = #H023$B5:3/2
;fetch and save remote bit
IF (($B0:0/1 .EQ. ON) .AND. (@TIM_CTL/T_DONE_BIT .EQ. OFF)) GOTO LOOP2
@PROCESS/P_ON_BIT = OFF
;turn process off
EXIT
Procedure -- @LOG_ERROR
;This procedure reads the error block out of the module status area and
;records it along with the time of day in status file 9.
CREATE @STATUS $S9
CREATE @ERR_BLK $E2.3.TH.3.5.4.0
CREATE @TOD $S1:3
@STATUS:(A) = @ERR_BLK,26
;copy error block (26 words)
@STATUS:(A) = @TOD,2
;copy time of day (hrs, mins)
IF ((ERROR .GE. 81) .AND. (ERROR .LE. 92)) GOTO NO_STN
;no station-fatal error
IF (A .GE. 252) GOTO TIMEOUT
;after ten errors, tell operator
A == A + 28
;update error pointer
EXIT
NO_STN:
$S4:3/5 = 1
;energize 1775-GA report generation message rung
STOP
;exit procedure with an error
TIMEOUT:
$S4:3/4 = 1
;energize 1775-GA report generation message rung
A==0
;clear error pointer
EXIT
;return to @REM_TURNON
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Message Procedures
The 300-second timer in the example procedure given in Figure 6.7 is not
an accurate, real-time clock. This is because the time between successive
executions of the bit/timer check depends on activity on the DH or DH+
and on the activity of the local PLC-3 controller.
For example, if the 300-second timer times out immediately after its done
bit is checked, the scanner does not detect this condition until its next pass
through LOOP2. If the link is busy with other activity, it takes a while for
LOOP2 to check the remote bit.
The example procedure also assumes that the referenced memory areas
have been created. Specifically:
1.
Status file S9 must be big enough to hold ten errors of 28 words each.
2.
Timer T1 is a one-second timebase timer. Bit B0:0/0 controls the
ladder rung that activates the timer. Figure 6.7 refers to this bit as
TIM_START/T_ON_BIT.
3.
Bit S4:3/4 and S4:3/5 activate message instructions that execute
report-generation procedures. In this way, the scanner can indirectly
cause execution of a report-generation procedure that displays a
message on the operator’s terminal.
6-21
Chapter
7
Diagnostics Methods
Chapter Objectives
This chapter describes how the scanner detects and reports various types of
errors. Appendix B lists all the errors reported by the scanner.
DH/DH+ Message Procedure
Diagnostics
Error Reporting
When an error occurs, the scanner automatically creates and stores the
error code in the interprocedural user symbol ERROR. You should reserve
the symbol ERROR exclusively for error reporting.
ERROR contains only the last error encountered during execution of a
command or message procedure. The scanner clears the ERROR symbol
whenever a procedure is finished, even a called procedure. If you want to
save the error code or manipulate it in any way, you can use an assignment
command to copy the code into a more permanent storage word.
Recovery from Errors
Unless you specify differently, the scanner stops executing the current
message procedure as soon as the module detects an error. To specify a
different action, use the ON_ERROR command in the message procedure.
Then, when the scanner encounters an error, it performs the action
specified in the nearest preceding ON_ERROR command. After the
module completes executing the ON_ERROR action, it resumes executing
the message procedure at the command line following the one in which the
error occurred.
For example, a message procedure can contain the command:
ON_ERROR @RECOVER
When an error occurs in the procedure, the ON_ERROR command causes
the scanner to execute the procedure named RECOVER. The procedure
RECOVER might be a routine for monitoring error codes. After executing
RECOVER, the scanner resumes executing the original procedure at the
command line following the one where the error occurred.
7-1
Chapter 7
Diagnostics Methods
Error Monitoring
To aid in error monitoring, the scanner maintains a 26-word-error block in
the module status area of memory. The extended address for the beginning
of the error block file is:
$E2.3.thumbwheel_number.3.5.4.0
You can access this error block by:
displaying it on the controller front panel (displayed in hex)
using the data monitor mode of your programming terminal
(displayed in hex)
using the move status (MVS) command in the ladder program
using procedure commands in the following modules:
- 1775-S5 or 1775-SR5 module
- 1775-GA module
- 1775-KA module
Error Block
This error block contains the following information:
Word
Contains the
0
last generated error code (see appendix B)
1
total number of errors that have occurred
27
error information for message task 1
813
error information for message task 2
1419
error information for message task 3
2025
error information for message task 4
Four groups of words are provided for the message tasks since the scanner
can execute four message instructions at once. Within each message task,
the words contain the following information:
7-2
Task Word
Contains the
0
error code for the last error that occurred in the message task
1
total number of errors that occurred in the message task
2
value 1
3
line number where the error occurred in the highest level (nest level 1)
message procedure
4
line number where the error occurred in the next highest level (nest
level 2) message procedure
5
line number where the error occurred in the lowest level (nest level 3)
message procedure
Chapter 7
Diagnostics Methods
The line number is the relative location of a command line from the
beginning of the message procedure containing the line. The first line of
each procedure is line number 1, and any following lines are numbered in
ascending sequence. Nested procedures begin with line 1 again, thus the
need for words 3, 4 and 5 in the error block.
Important: You do not enter the line numbers for a procedure; the scanner
automatically keeps track of the line numbers for you.
The error block retains its data even after the message procedures complete
execution. The block does not reset automatically.
Error Block Operation
Figure 7.1 illustrates how the error block works. In this figure, an
addressing error (invalid destination address) occurs in procedure SUB2,
which is nested 3 levels deep.
Word:
of the error code gives the line number where error occured in procedure:
5
SUB2.
4
SUB1 that executed procedures SUB2.
3
MAIN that executed procedure SUB1.
7-3
Chapter 7
Diagnostics Methods
Figure 7.1
Error Block Operation
Line Number
Procedure
Word
Error Block
Contents (decimal)
0
124
MAIN
•
•
•
150
@SUB 1
•
•
•
2
SUB 1
28
•
•
•
1
1
3
150
4
28
@SUB 2
•
•
•
5
SUB 2
5
1
5
•
•
•
6:12 = COUNT
•
•
•
11247
ON_ERROR or IF commands can contain an embedded command to
execute another procedure. In these cases, the scanner treats the embedded
execute command just like a nesting level (Figure 7.2).
7-4
Chapter 7
Diagnostics Methods
Figure 7.2
Example Procedures Showing ON_ERROR Nesting
Line Number
Procedure
Word
Error Block
Contents (decimal)
MAIN
1
ON_ERROR @SUB1
0
160
7.2 = 1000
1
2
2
1
3
1
4
8
5
0
•
•
10
•
•
•
SUB1
8
•
•
•
•
•
$25:0 = N
•
•
11248
In this example (Figure 7.2), an addressing error in line 10 of procedure
MAIN causes the ON_ERROR command to execute. The ON_ERROR
command calls for execution of procedure SUB1. But SUB1 also contains
an error. The error in SUB1 is the last one detected, so it is the one finally
reported in the error block. Since procedure SUB1 is called by the
ON_ERROR command in procedure MAIN, the nesting for SUB1 is 2
levels deep.
7-5
Chapter 7
Diagnostics Methods
Diagnosing Faults with
Module Status Indicators
All PLC-3 modules have two self-test indicators. Table 7.A describes how
to interpret these indicators.
Table 7.A
Module Selftest Indicators
Indicator and Status
PASS
FAIL
Description
ON
OFF
Normal operation
OFF
ON
Module fault
ON
ON
Powerup or system reset
OFF
OFF
Processor shut off
The scanner modules have several indicators to monitor its status
(see Figure 7.3).
Figure 7.3
Indicator Locations for 1775S5 and 1775SR5 Scanner Modules
1775SR5
Scanner
1775S5
Scanner
PASS and FAIL indicators
Thumbwheel switch
Forces enabled indicator
I/O channel
status indicators
DH/DH+
status indictors
18751
7-6
Chapter 7
Diagnostics Methods
Remote I/O Adapter Faults
(Status File 2)
Figure 7.4 shows the word organization for status file 2.
Figure 7.4
Remote I/O Device Fault Status Bits (Status File 2)
17
16
15
14
13
12
11
10
07
06
05
04
03
02
01
00
Word 0
I/O Rack
Starting
I/O group
0
0
2
4
6
1
0
2
4
6
2
0
2
4
6
3
0
2
4
6
To find the word that stores the fault bits for an I/O adapter:
Rack # in decimal = word in file 2 containing fault bits for the adapter.
4
The remainder tells you the bit numbers within the word:
0 - bits 00 to 03
1 - bits 04 to 07
2 - bits 10 to 13
3 - bits 14 to 17
For example, the fault bits for I/O rack 10 are in word 2 (S2:2), bits 10 to 13.
15180
Important: The processor does not create status file 2 at power-up. You
must create it in memory by using the create command.
7-7
Chapter 7
Diagnostics Methods
I/O Communication Retry
Counts (Status File 3)
A communication retry is a re-transmission of data that occurs when the
original transmission is unsuccessful. If the I/O adapter does not respond
or sends invalid data when the scanner communicates to the I/O adapter,
the scanner executes a retry.
You can track the retry count by monitoring status file 3 (see Figure 7.5).
Figure 7.5
I/O Communication Retry Counts (Status File 3)
17
16
15
14
13
12
11
10
07
06
05
04
03
02
01
word 0
word 1
00
Starting
Adapter # I/O group
0
0
2
4
6
1
0
2
4
6
word 2
word 3
word 4
word 5
word 6
word 7
.
.
.
word n
To find the word that stores the retry count for an I/O adapter:
Adapter # in decimal x 4 = the first of the words that stores the retry
counts for the adapter. The particular
word depends on the starting I/O group.
For example, the retry counts for adapter 10 are in words 40 to 43 (S3:40 to S3:43)
15181
Important: The processor does not create status file 3 at power-up. You
must create it in memory by using the create command.
If the retry count is high for an I/O channel, check to see if it is caused by
one of the following:
loose connection with the twinaxial cable (cat. no. 1770-CD) that
connects from the scanner’s terminal arm to the I/O adapter
noise problem with the twinaxial cable (cat. no. 1770-CD) that connects
from the scanner’s terminal arm to the I/O adapter
improper installation of I/O terminator resistors along the I/O channel
Refer to the PLC-3 Family Controller Installation and Operation Manual
(publication 1775-6.7.1) for detailed information.
7-8
Chapter 7
Diagnostics Methods
Upon executing a retry, if the I/O adapter responds properly, normal
operation continues. If the I/O adapter does not respond properly, the
scanner continues to execute retries until:
the I/O adapter returns a valid response, or
the processor declares a major or minor I/O fault based on how you
configure the rack list in LIST.
Adapters on channel:
Number of consecutive retries that execute
before the processor declares an I/O fault:
1
10
2
8
3 to 7
6
8 to 16
4
If the processor declares an I/O fault, it sets the following bits:
I/O adapter fault status bit file 2 that corresponds to the I/O adapter
major or minor I/O fault bit in system status
The scanner continues scanning the I/O chassis. When it returns to the
faulted I/O adapter, it attempts to reset the input or output and moves on to
the next I/O adapter.
Important: Upon declaring a major or minor I/O fault, if normal
communication returns to the I/O adapter, the processor does not reset the
I/O adapter fault bit in status file 2 or the major I/O or minor I/O fault bit
in system status.
If you do not want normal communication to return to a faulted I/O
adapter, set the processor-reset-lockout switch on the I/O chassis. With
this switch set, the I/O adapter does not reply to the scanner once a fault is
declared until you cycle power at the I/O chassis or press the reset button
on the I/O adapter.
Retries for a PeertoPeer or
Backup Communication
Channel
If you configure an I/O channel for peer-to-peer or backup communication,
and communication problems occur between two scanners (master, slave,
primary, or backup) on the channel, a retry executes. If the communication
occurs properly, normal operation continues.
If communication problem continues to occur, the scanners:
set the peer-to-peer or backup communication minor fault status bit in
system status
flash the LED corresponding to the channel on their front edges
7-9
Chapter 7
Diagnostics Methods
Also, the scanner configured as the master on a peer-to-peer
communication channel declares a peer-to-peer communication minor fault
when it cannot successfully communicate with a slave after two
consecutive retries.
Important: Once set, the peer-to-peer and backup communication minor
status bit remain set until you reset it.
Table 7.B
I/O Channel Indicators for All Scanner Modules
Indicator
Status
CHx
ON
Configured for
I/O Scanning
FLASHING
There is a fault on one or more of the I/O chassis on the
corresponding I/O channel.
OFF
No I/O chassis are configured on the corresponding I/O
channel or the channel is inactive.
CHx
ON
The channel is functioning properly.
Configured for
peertopeer
communication
FLASHING
CHx
Configured for
backup
communication
Communication between scanner module and the I/O chassis
on the corresponding I/O channel is properly established.
The input file is too small at the processor receiving data. The
slave or master does not exist. Communication retry.
OFF
The channel is inactive.
ON
The channel is functioning properly.
FLASHING
OFF
DH/DH+ Indicators
Description
The input file is too small at the processor receiving data. The
partner is not responding.
The channel is inactive.
Table 7.C shows the DH/DH+ status indicators for 1775-S5, -SR5
scanner modules.
Table 7.C
DH/DH+ Status Indicators for 1775S5, SR5 Scanner Modules
7-10
Indicator
Status
Description
XMTG
ON
transmitting a message
RCVG
ON
receiving a message
RDY
ON
ready to transmit a message
ERR
ON
programming or communication error detected
DIS
ON
DH/DH+ channel is disabled
Chapter 7
Diagnostics Methods
Important: When the scanner is polling, both the XMTG and RCVG
LEDs trun on. Also, if there is a duplicate node on DH+, the yellow
disable indicator blinks until the condition is removed.
DH/DH+ Diagnostic
Assignment Command
The scanner can send out DH and DH+ diagnostic commands using a
special format of the assignment command. As with other assignment
commands, you can program this command directly into the message
instruction or use it within a DH/DH+ procedure.
ATTENTION: If the diagnostic assignment command is not
properly programmed, unanticipated data can be sent to remote
stations on the DH or DH+ link causing unpredictable
operation.
This assignment command requires that data table be reserved for both the
command to be sent and the response that will be returned from the remote
station. You must reserve a minimum of 126 words of data table for
the response.
The command is formatted as follows (note the special use of the
exclamation point):
$B0:0 = !H023 $B1:0
command block location
destination
response block location
Where:
Is the:
response block
location
starting address of the data table address which will be
used to save the response data from the remote station.
destination
remote station address to where this command is being
sent. This address can be any remote station address and
can include a bridge address when using DH+
(for example !H1:2:3).
command block
location
Starting address of the data table address which contains
the command being sent to the remote station.
7-11
Chapter 7
Diagnostics Methods
Revision A/F or later scanners execute the diagnostic assignement
command, however the command block configuration was modified with
the release of the A/H scanner. Table 7.D and Table 7.E show the
command and response that are stored as a series of bytes with the
following meaning:
Table 7.D
Command Block
Byte
Meaning
1&2
number of bytes minus one to follow this word
3&4
no care byte and command byte
5&6
status byte (always zero) and tns byte (always zero)
7&8
tns byte (always zero) and function byte
9 thru n
command data dependent on command & function
Table 7.E
Response Block
Byte
Meaning
1&2
no care byte and status byte (00 = success)
3&4
number of bytes to follow this word
5&6
command byte and status byte
7&8
tns word
9 thru n
response data (stored low byte/ high byte)
You can use the following diagnostic commands with the diagnostic
assignment command:
Command
7-12
Command Byte
Function Byte
Diagnostic Loop
06
00
Diagnostic Status
06
03
Diagnostic Read
06
01
Diagnostic Counters Reset
06
07
Chapter 7
Diagnostics Methods
Diagnostic Loop Command
You can use this command to check the integrity of transmissions over the
communication link. The command message transmits up to 243 bytes of
data to a remote station. The receiving station should reply to this
command by transmitting the same data back to the scanner.
For example:
Command block in data table:
0012 0006 0000 0000 0102 0304 0506 0708 090A 0B0C 0D00
Response block in data table:
0000 0011 4600 0200 0102 0304 0506 0708 090A 0B0C 0D00
Diagnostic Status Command
You can use this command to read a block of status information from the
remote station. The reply to this command contains the diagnostic status
information in the response data. Each remote station defines the data sent
back in response. The scanner sends back 18 bytes as defined in
Table 7.H.
For example:
Command block in data table:
0005 0006 0000 0003
Response block in data table:
0000 0016 4600 0300 0246 1003 5088 5E00 4002 0000 111B
0400 0000
Diagnostic Read Command
You can use this command to read the remote stations diagnostic counters.
Use the diagnostic status command to obtain the starting address of the
diagnostic counters.
The first two bytes of the command data is the address of the counters (low
byte/high byte) as returned from a diagnostic status command. The third
byte is the number of bytes to be returned; 18 bytes for the scanner.
The response data contains the diagnostic counters. The scanner DH
counters are defined in Table 7.F and DH+ counters in Table 7.G.
Command block in data table:
0008 0006 0000 0001 5E00 1200
Response block in data table:
0000 0016 4600 1700 7E4B 7F4B 0000 0000 0000 0000 0000
0000 0000
7-13
Chapter 7
Diagnostics Methods
Diagnostic Counters Reset Command
Use this command to reset to zero all the diagnostic counters in the remote
station.
Command block in data table:
0005 0006 0000 0007
Response block in data table:
0000 0004 4600 1900
Table 7.F
DH Diagnostic Counters
7-14
Byte:
This counter increments when the scanner:
1
receives an ACK with a bad CRC
2
does not receive an ACK before the timeout value
3
while master, detects a message transmission by another station
(contention)
4
receives an error in the received ACK
5
adds errors in bytes 1, 2, and 4
6
receives a WAK when no receive buffer space is available at the
remote station
7
does not detect a master on the link before its timeout period expires
and so assumes mastership
8
as master, does not receive a reply from its polling sequence that has
been narrowed done to a single station
9
receives an ACK even though it does not have mastership
10
receives an illegal packet of less than 6 bytes
11
receives a packet with an incorrect destination or a packet in which the
source is equal to the destination
12
(not used)
13
receives a packet with a bad CRC
14
received a frame that was beyond the legal limit of 250 bytes
15
does not have the buffer space for a received message
16
received a message that was previously received
17
received aborted frame (line noise)
18 & 19
successfully sent a message
20 & 21
successfully received a message
22 & 23
successfully sent a command
24 & 25
successfully receives a reply
26 & 27
successfully receives command
28 & 29
successfully sends a reply
30
can not send a reply
Chapter 7
Diagnostics Methods
Table 7.G
DH+ Diagnostic Counters
Byte:
This counter increments when the scanner:
1&2
successfully sent a message
3&4
successfully received a message
5
can not deliver a message due to a NAK or after using up maximum
retries
6
did not receive a response before the response timeout value was
reached
7
received a NAK
8
must send a message retry as a result of CRC error, illegal length, not
its destination, the source was not the expected station, or a timeout
9
sent a NAK because there was no memory available
10
sent a NAK because of the received message contained an undefined
LSAP
11
receives a message which was received previously
12
has to send a token pass retry
13
receives an aborted packet
14
receives a packet that had a CRC error
15
receives an illegal size packet which was either less than 3 bytes or
larger than 271 bytes
16
detects a duplicate token on the link
17
recovers from a duplicate node condition
18
detects a link dead timeout
7-15
Chapter 7
Diagnostics Methods
Table 7.H
Data Sent in Response to a Diagnostic Status Command
Byte:
Bit:
1
Description:
Operating status of PLC-3 processor
0-1
00 = Program mode
01 = Test mode
10 = Run mode
2
Not used
3
0 = Normal
1 = Major processor fault
4
0 = Normal
1 = Shutdown request
5
0 = Normal
1 = Shutdown in effect
67
Not used
2
Type of station interface and processor
03
6 = scanner
47
4 = PLC-3 processor
3
all
Current context stored in bits 4 thru 7
4
all
Thumbwheel
56
all
Mode control word
The extended address of the mode control word is E0.0.0.8
78
all
9
Starting byte address of the diagnostic counters.
Series and revision number of the module.
Even though the scanners are series A, they appear as series E modules
03
0 = Revision A scanner
1 = Revision B scanner
etc.
47
0 = Series A
etc.
10
1114
1 = Series B
Type of channel communications
01
0 = Inactive
1 = DH
2 = DH+
3 = other
23
0 = A/G or earlier S5 or SR5
1 = A/H or later S5
2 = A/H or later SR5
3 = unused
47
unused
all
The physical address of the unused word of PLC-3 system memory.
This is the physical address corresponding to the extended address
E60.0.0.0
1518
7-16
all
The total number of words in the PLC-3 system memory
(both used and unused)
Appendix
A
Binary Command Language
Introduction
The scanner communicates through the peripheral channel 0 on front panel
with a programming device or another external control device such as a
computer. The scanner uses the binary command language (BCL) for
communication. This chapter describes the protocol and commands of
BCL, and briefly reviews PLC-3 addressing.
Protocol
BCL is a master/slave communication protocol in which the scanner is the
slave and the external device must act as the master. As slave, the scanner
cannot initiate any communications. The BCL protocol defines the rules
of communication between the scanner and an external control device. It
includes the:
method of initiating communication
format in which information must be sent to the scanner
format of scanner responses
amount of time which may elapse between commands without causing
the scanner to declare a channel timeout and stop communicating
Timeouts
BCL protocol uses four timeouts to determine if a communication problem
occurs. These timeouts guard against stopping or unnecessarily slowing
down the scanner or the master device when communication is terminated
unexpectedly (such as when a cable is detached).
If you see:
It means:
Channel Timeout
scanner waiting for command
Character Timeout
master or scanner waiting for next character in block
Response Timeout
master waiting for response block after ACK
Acknowledge Timeout
master or scanner waiting for ACK
A-1
Appendix A
Binary Command Language
Channel Timeout (Scanner waiting for command)
A channel timeout occurs when the scanner is waiting for a command and
does not receive one within the specified time.
You can select the channel timeout through the LIST function. The front
panel timeout value defaults to 10 seconds. Selecting a value of zero
disables the channel timeout.
When a channel timeout occurs, the scanner stops communicating through
channel 0. The master must then re-initialize the communication.
Character Timeout (Master or scanner waiting for next character
in block)
A character timeout occurs when the time between characters (bytes) in a
command block, response block, CCR, or CCR response is greater than the
character timeout value.
The master can set the scanner’s character timeout value by sending the
desired value within the CCR. If the master sends a zero value, the scanner
defaults to the character timeout value appropriate for the current
communication rate configuration as shown in Table A.A.
Table A.A
Communication Rate Configuration
Communication Rate (bps)
Character Timeout Default Value
110
1 second
150
600 ms
300
300 ms
600
150 ms
1200 to 19.2
80 ms
If the master or a scanner records a character timeout, it must be treated as
if a NAK were received. They stop transmitting for one character timeout
value and then reissue the command or response.
The scanner sends a NAK when it detects this timeout.
A-2
Appendix A
Binary Command Language
Response Timeout (Master waiting for response block after ACK)
A response timeout occurs when the scanner does not send a response
block back to the master within a given time after acknowledging receipt
of a command block.
The master device determines the time allowed ( the scanner is not aware
of this timeout). Typically, a one minute response timeout provides
enough time for the scanner to respond without unnecessarily slowing the
master device.
After a response timeout, the master device:
sends a CCR to the scanner
checks the protocol fault code in the CCR response (refer to Table A.A)
If the fault code is:
The master device:
00 hex (no fault) or 05 hex (no input buffer
available)
clears its error count and retransmits the
last block.
another fault code (besides 00 or 05 hex) or
if the scanner does not respond to the CCR
within one character timeout period
terminates communication or tries to
reinitialize communication.
Acknowledge Timeout (Master or scanenr waiting for ACK)
The maximum amount of time the scanner waits for an ACK, NAK, or SO
from the other device after sending a response or command is 2 seconds
(S4A used character timeout value). Master must also select a value for
this timeout.
This timeout should be treated as if a NAK were received. The driver stops
transmitting for one character timeout value and then reissues the
command or response.
A-3
Appendix A
Binary Command Language
Circuit Control Request (CCR)
The master uses the circuit control request (CCR) to initiate, reset, or
verify communications with the scanner. The CCR consists of five bytes
of data defined as follows:
STX
Control Code
Character
Timeout Value
ETX
Checksum
Command:
Description:
STX (start of text)
the first byte of the control block (02 hex).
Control code
In the control code byte, bits 7, 6, 5, and 4 contain the value 1, 0,
0, and 0 respectively. This is necessary for the scanner to
recognize the byte as a control code. The meaning of the other
bits in the control code is as follows:
1
0
0
0
X
X
X
X
set timeout value
reset command block seq cntr
reset response block seq cntr
reset communications
A-4
Character Timeout Value
The third byte is the character timeout value. If bit 3 in the above
control code is set, this byte sets the character timeout value. The
timeout is 10 ms times the value in this byte, which allows timeout
values between 10 and 2550ms. If bit 3 in the control code is not
set, this byte is zero. A zero in this byte causes a default
character timeout as shown in Table A.A.
ETX (End of Text)
03 hex.
Checksum
The fifth and last byte in the CCR is a checksum. The checksum
is the least significant eight bits of the sum of the previous four
bytes in the CCR.
Appendix A
Binary Command Language
Circuit Control Request Response
The scanner response to a master’s CCR is a fourteen byte response.
STX
Control
Code
Number
of
Bytes
Current
command
block seq
Mod Type
and
thumbwheel
Current
response
block seq
Series
Character
timeout
value
Rev
Protocol
fault code
Max
command
block size
ETX
Max
response
block size
Checksum
Command:
Description:
STX (start of text)
the first byte of the control block (02 hex).
Control Code
Value echoes the control code (byte two) of the
CCR.
Length of response block
Count of the remaining bytes including this byte and
the ETX.
Module type and thumbwheel number
Module type in the upper four bits and the
thumbwheel number in the lower four bits.
Scanner Series
Scanner module's series number.
Scanner Revision
Scanner module's revision number.
Maximum command block size
Scanner module's maximum command block size in
bytes.
Maximum response block size
Scanner module's maximum response block size in
bytes.
Current command block sequence
The current command block sequence count as
maintained by the scanner.
Current response block sequence
The current response block sequence count as
maintained by the scanner.
Character timeout value
The character timeout value in 10's of ms. If zero
then see Table A.A for default.
Protocol fault code
The protocol fault code. The possible fault codes
are listed in Table A.B.
ETX (End of text)
03 hex.
Checksum
The last byte in the CCR response is a checksum.
The checksum is the least significant eight bits of
the sum of all the above bytes in the response.
A-5
Appendix A
Binary Command Language
Table A.B
Fault Code
HEX fault code value
Description
00
No fault
01
Checksum error
02
Format fault - missing ETX
03
Format fault - other
04
Input buffer overflow
05
No input buffer available
06
Previous buffer still in progress
07
Command block sequence count error
08
Receiver error
FF
Unknown protocol failure
Block Sequence Counts
Both the master and scanner maintain a command block sequence count
and a response block sequence count. These counters are separate entities
and do not necessarily agree. The scanner:
checks the command block sequence when received
compares it to its own version of the command block sequence count
increments the command block sequence count when a valid command
is received.
The response block sequence count is incremented and sent out by the
scanner. The master checks the response block sequence count when
received and compares it to its own version of the response block
sequence count.
A-6
Appendix A
Binary Command Language
Command Block
With the exception of the CCR, all commands sent from the master to the
scanner are in the form of a command block. The command is always
structured as follows:
STX
(02)
Command
Block Seq
Count
Command
Buffer Size
Command
Command Data
ETX
(03)
Checksum
command buffer
Command:
Description:
STX (start of text)
the first byte of the control block (02 hex).
Command block sequence count
Command block sequence count (0 to 7F hex)
Command buffer size
Number of bytes to follow in the command buffer. The
buffer includes all bytes between this buffer size byte and
the ETX.
Command
The fourth byte in the command block contains the hex
code corresponding to the desired command.
Command data
The command data contains all parameters associated
with the indicated command. When the command data
contains data in word format, the lower byte must be sent
first.
Important: The master can send multiple
commands in one command buffer by including another
command and command data after the previous one.
Each command must have all necessary parameters and
the entire command block cannot be larger than the
scanner is capable of receiving. This maximum size
should be one less than is reported in a CCR response.
One word is reserved for scanner use.
ETX (End of text)
Following the command buffer is the ETX code (03 hex).
Checksum
The last byte is a checksum which is the sum of all
previous bytes from the STX (02) through ETX (03)
inclusively.
A-7
Appendix A
Binary Command Language
Response Block
With the exception of the CCR response, all responses from the scanner to
the master are in the form of a response block. The response is always
structured as follows:
STX
(02)
Response
Block Seq
Count
Response
Data Buffer
Size
Response
Code
Response Data
ETX
(03)
Checksum
response buffer
Command:
Description:
STX (start of text)
the first byte of the control block (02 hex).
Response block sequence count
Response block sequence count (0 to 7F hex).
Response buffer size
Number of bytes to follow in the response buffer.
The buffer includes all bytes between this buffer
size byte and the ETX.
Response code
This byte contains the scanner's reaction to the
previous master's command in the form of a
response code. Table A.C outlines the response
code possibilities.
Response data
The response data includes response parameters
associated with the previous command as received
from the master. When the response data contains
data in word format, the lower byte is sent first.
Important: The scanner can send multiple
responses in one response buffer provided that
each response has all necessary parameters.
A-8
ETX (End of text)
Following the response data buffer is the ETX code
(03 hex).
Checksum
The last byte is a checksum which adds from the
STX (02) through ETX (03) inclusively.
Appendix A
Binary Command Language
Table A.C
Response Code
HEX code
Response
Description
00
Success
Operation was completed as requested.
01
Size Too Big
Operation stopped because the response was too big to fit in the
response block. Success or failure depends on the operation.
02
Available
Interpretation of this response depends on the operation. See the
appropriate command descriptions for details.
03
Unavailable
Interpretation of this response depends on the operation. See the
appropriate command descriptions for details.
04
Address Does Not Exist
The specified address has not been allocated.
05
Address Invalid
This response is returned when the specified start address is valid, but
another address used in the operation has not been allocated.
06
Access Not Allowed
The channel does not have access to the area specified for the
purpose requested.
07
Allocated
The function or resource requested is allocated and therefore
unavailable (unless it is already allocated to your channel).
08
Address Not Complete
The address given is not specified to a low enough level to perform
the requested function.
09
Unknown Command
The scanner does not recognize the command code.
0A
Invalid Parameter
A parameter in the command block is invalid.
0D
Processor Error
0E
Processor Error
0F
No Privilege
One or more privileges required for the attempted operation are not
assigned to the channel.
FF
Unknown Failure
The function failed for a reason which cannot be described by any
other response code.
Initializing Communications
To initiate communications with the scanner the master sends a break
character followed by a CCR. The CCR should have the reset
communications bit (bit 0) of the control code set. This instructs the
scanner to return to its initial communications state, including resetting the
command block sequence and the response block sequence count.
The master must see break go away before sending the CCR. The scanner
sends break for a character timeout period. The scanner identifies a break
character as any high state (voltage) which remains on the line longer than
the time required to transmit one character (byte). The approximate
character times are listed in Table A.D.
A-9
Appendix A
Binary Command Language
Table A.D
Approximate Character Times
Communication
Rate in bits/s
Approximate character transmit time
10 bit character
8 bit character
110
91.0 ms
72.7 ms
150
66.7 ms
53.3 ms
300
33.3 ms
26.7 ms
600
16.7 ms
13.3 ms
1200
8.3 ms
6.7 ms
1800
5.6 ms
4.4 ms
2400
4.2 ms
3.3 ms
4800
2.1 ms
1.7 ms
9600
1.0 ms
0.83 ms
19200
0.52 ms
0.41 ms
The break character tells the scanner to terminate any previous
communication. Therefore, send a break character whenever you initiate
or terminate communication. Both the scanner and the master device
respond to a break at any time by stopping transmission (even in the
middle of a block).
Although not configurable on the scanner, some PLC-3 family modules
which use BCL, can also be configured for BREAK DISABLED. This
option is selected when the master is not capable of detecting a break sent
from the PLC-3. When the channel is configured with BREAK
DISABLED, the master must send break for a minimum of one second.
If the master device does not support a break character, you can initiate
communications by sending a valid command to the scanner.
Important: If you use this method, remember that the PLC-3 scanner may
not be in its initial communication state when you begin communicating
with it. This can cause the PLC-3 to respond with invalid results until a
timeout or other error causes it to terminate communication, return to its
initial state, and start over.
A-10
Appendix A
Binary Command Language
Communication
The scanner must supply an ACK or NAK within one character timeout
period of receiving a command block. As the slave on the link, the scanner
has until a response timeout occurs before issuing a response block.
If the scanner receives a command block correctly, it responds with an
ACK code (06 hex) and increments the command block sequence count.
The master also increments the command block sequence count and resets
the error count at this time.
If the scanner detects an error in the command block which it receives, it
responds with a NAK code (15 hex). Some typical reasons for sending a
NAK are as follows:
received invalid command block sequence count
unexpected command block
unable to handle command block at this time
character timeout value exceeded
The master stops transmitting within one-half of the character timeout
period after receiving the NAK code. The master increments its error
count and:
If the error count is:
The master:
less than three
retransamits the block after one character timeout period.
three
stops trying to transmit the block.
If the master does not receive an ACK or NAK code within one character
timeout period after transmitting the command block, it continues as
though it received a NAK.
Handshaking
After receiving a response block from the scanner the master responds
within a character timeout period with one of these codes:
If you see:
It means that:
ACK (06 hex)
the command block was received correctly and that normal
communication is to continue.
NAK (15 hex)
an error was detected in the response block and instructs the scanner to
retransmit the block. The scanner tries three times before terminating
communication.
SO (0E hex)
shift out
the master needs time to process the response, and instructs the scanner
to wait. The scanner must wait for the master to send a shift in character
(0F hex) before continuing communication. A shift in character indicates
that the master is ready to continue communication.
A-11
Appendix A
Binary Command Language
When the master is ready to restart communication with the scanner:
It sends a shift in character.
The scanner echoes the shift in character and resumes communication.
If the scanner does not echo the shift in character within one character
timeout period, the master device assumes that the character is not
received, and retransmits up to a maximum of three times.
After 3 unsuccessful attempts, the master sends a CCR to the scanner
and checks the protocol fault code in the CCR response. If the fault
code is:
00 hex (no fault) or 05 hex (no input buffer available), the master
should clear its error count and retransmit the last block.
Any other fault code returns, or if the scanner does not respond to
the CCR within one character timeout period, the device should
terminate communication.
Protocol Summary
Figure A.1 summarizes the protocol used with BCL. To read this diagram:
Use the:
To see
left column
what the processor expects to receive from your device
second column
possible processor responses to your transmission
each remaining column
either
• a processor response
or
• the action which the processor expects your device to
take in response to its last transmission
Important: Both the processor and the external device must respond to a
break at any time. Figure A.1 shows break conditions after each
transmission, but be aware that either the processor or the external device
stops transmitting (even in the middle of a block) when it sees a break.
A-12
Appendix A
Binary Command Language
Figure A.1
BCL Protocol Diagram
External Device
PLC3
CCR or
Command Block
ACK
External Device
PLC3
External Device
PLC3
External Device
1
Break
Terminate
Communication
Character
Timeout
To Sheet 2
Invalid
Response
NAK
Channel
Timeout
Terminate
Communication
Break
Terminate
Communication
Fault Code
No
Response
Timeout
3rd
Try?
CCR
CCR
Response
00 Hex
05 Hex
Other
Yes
Character
Timeout
Break
Terminate
Communication
2
From Sheet 2
From Sheet 1
1
PLC3
Response Block
or CCR Response
External Device
PLC3
External Device
PLC3
Break
Shift
Out
Terminate
Communication
Shift
In
Break
Invalid
Response
3rd
Try?
NAK
External Device
Terminate
Communication
Other
Yes
Are
There
More Blocks
in the
Response
?
No
Terminate
Communication
Character
Timeout
Yes
No
2
PLC3
Shift
In
Character
Timeout
To Sheet 1
External Device
ACK
Break
Terminate
Communication
Channel
Timeout
Terminate
Communication
Fault Code
3rd
Try?
No
Yes
CCR
CCR
Response
00 Hex
05 Hex
Other
Character
Timeout
Break
Terminate
Communication
Will Not Occur During
Multiple Block Responses
A-13
Appendix A
Binary Command Language
Extended Addressing
Most BCL commands and responses that require an address as one of the
parameters use the extended address format. The exceptions are:
read I/O word command which requires an I/O address
read block physical and write block physical commands (used for
uploading and downloading respectively) which use physical addresses
A detailed description of processor extended addressing appears in the
PLC-3 Family Controller Programming Manual (publication 1775-6.4.1).
Processor memory organization is summarized in Table A.E.
When you send an extended address to the processor, it must follow a
mask byte. The mask byte tells the processor which address levels the
following address defines and which levels default.
A bit in the mask which is set to:
Indicates that the:
1
corresponding level of memory is specified in the
address to follow
0
default value is used for the corresponding level
of memory
Bit 0 in the mask corresponds to the major area. Bits 1 to 7 in the mask
each correspond to the next level in the specified section.
For example, in the data table (area 3), bit 1 corresponds to the context and
bit 2 corresponds to the data table section (e.g., output, input).
You can extend the mask byte into a mask word to specify more than 7
levels of an address by sending a byte with the value FF hex followed by
two bytes of the mask word. This is for future expansion of processor
extended addressing, as only 6 levels are presently used (Table A.E).
The default value for:
Is :
the major memory area (bit 0)
3 (data table)
context (bit 1)
initially the context that the processor is operating
when communication is established
all other memory levels
0
You can change the default context by using the set operating context
command. Unless otherwise specified, examples in this chapter assume
that the default context is 1. You can use the default for any level except
the lowest level of the address.
A-14
Appendix A
Binary Command Language
Table A.E
Extended Addressing
Area
E#
.x
.x
.x
.x
.x
system status
E0
context = 0
section = 0
word = 0 20
not used
not used
module status
E2
module type =
1 - memory
2 - main processor
3 - scanner
5 - communication
adapter
6 - expansion
7 - S4B I/O scanner
8 - peripheral
communication
9 - DH II
interface
14 - memory
communication
thumbwheel switch =
1 15
module data
module data
module data
data table
E3
context = 1 15
section =
1 - output image
2 - input image
3 - timers
4 - counters
5 - integers
6 - floating point
7 - decimal
8 - binary
9 - ASCII
10 - high order int.
12 - pointers
13 - status
file =
0 999
0 999
0
0
0 999
0 999
0 999
0 999
0 999
0 999
0
0 999
structure =
0
0
0 9999
0 9999
0
0
0
0
0
0
0 9999
0
word =
0 07777 octal
0 07777 octal
0 CTL, 1 PRE, 2 ACC
0 CTL, 1 PRE, 2 ACC
0 9999
0 = lower 16 bits, 1 = upper 16 bits
0 9999
0 9999
0 9999
0 = lower 16 bits, 1 = upper 16 bits
0 = section/file, 1 = word
0 9999
ladder program
E4
context = 1 15
section =
0 program status
1 main
2 subroutine
3 fault routine
rung =
0 32, 767
instruction =
0 32, 767
word =
0 32, 767
message
E5
context = 1 15
section =
1 report generation
2 rung comments
3 terminal (MACROS)
4 DH
5 assistance (HELP)
message =
0 32, 767
word =
0 32, 767
not used
system
symbols
E6
context = 1 15
type = 1
symbol =
0 32, 767
word =
0 32, 767
not used
converted
procedures
E8
context = 1 15
section =
1 report generation
message =
0 32, 767
word =
0 32, 767
not used
force table
E10
context = 1 15
force type =
0 status
rack =
not used
word = 0
1 forced output
2 forced input
0 64
0 64
0 15
0 15
bit =
0 input forces enabled/disabled
1 output forces enabled/disabled
not used
not used
A-15
Appendix A
Binary Command Language
For example, two ways to send the address E3.1.2.0.0.0 are:
send the mask 3F16 (00111111) followed by the bytes 0316, 0116, 0216,
0016, 0016, 0016
send the mask 2416 (00100100) followed by the bytes 0216, 0016
You can extend address bytes into address words just as you extend mask
bytes into mask words. For example, the mask 2416 followed by the bytes
0216, FF16, 0016, 0816 corresponds to the address E3.1.2.0.0.2048.
Commands
The scanner supports commands for the following functions:
reading, writing, and verifying data
reading the size of memory sections
adding, expanding, deleting, or reducing sections
setting processor operating mode
accessing the LIST function
setting the default context for communication
The sections that follow describe each of these functions.
Reading Data
You can read data from the processor either in individual words using the
read word command, or in blocks using the read block command. You can
also read from the data table I/O section using the read I/O word
command. This command obtains an I/O word and the associated force
information from the processor. The byte increment/decrement command
adds or subtracts one to a specified byte. We describe these four read-type
commands in the following subsections.
A-16
Appendix A
Binary Command Language
Read Word Command
Hex: 12
Parameters: Address of required word
Description: The following example command block reads file 0, word 3
of the data table status section:
STX
02
ISC
05
SIZ
04
CMD
12
DAT
0D
24
03
ETX
03
CHK
54
The data bytes store:
address mask (24 hex)
address byte specifying status section 13 (0D hex)
address byte specifying word 3 (03 hex)
The processor responds with one of the following codes:
Response Codes
Hex
Description
00
Success
04
Address unknown
06
Access not allowed
08
Address not complete
If a success code is returned, the next two bytes in the response block
contain the data stored at the requested address, with the lower byte
sent first:
STX
02
OSC
01
SIZ
03
RSP
00
DAT
05
08
ETX
03
CHK
16
The data bytes store the data word:
lower byte (05 hex)
upper byte (08 hex)
If any other code returns, no data follows.
A-17
Appendix A
Binary Command Language
Read Block Command
Hex: 1F
Parameters: Starting address, size (in words) of the block
Description: The read block command reads a block of information
starting at a specific address. If you specify 0 for the size, the processor
returns the data from the address specified to the end of the section if this
does not include more than 63 words, or 63 words starting with the address
specified if the section is larger. The following example command block
reads the first two words of the input section:
STX
02
ISC
01
SIZ
08
CMD
1F
3C
02
00
DAT
00
00
02
00
ETX
03
CHK
6D
The data bytes store:
address mask (3C hex)
address byte specifying section 2 (input) (02 hex)
address byte specifying file 0 (00 hex)
address byte specifying structure 0 (00 hex)
address byte specifying word 0 (00 hex)
lower byte of size word (02 hex)
upper byte of size word (00 hex)
Notice that the size is specified in a word (two bytes). This is true of all
size specifiers within the data buffer of a command block.
The processor responds to a read block command with one of the
following response codes:
Response Codes
Hex
Description
00
Success
01
Size too big
04
Address unknown
05
Address invalid - end of section
06
Access not allowed
08
Address not complete
If a success, size too big, or address invalid – end of section code
returns, the next byte contains the number of data words returned. The
data follows this byte.
A-18
Appendix A
Binary Command Language
A success code returns when the number of data words returned equals the
number requested. For example:
STX
02
OSC
01
SIZ
06
RSP
00
02
04
DAT
03
0F
02
ETX
03
CHK
26
The data bytes store:
size byte (02 hex)
lower byte of the first data word (04 hex)
upper byte of the first data word (03 hex)
lower byte of the second data word (0F hex)
upper byte of the second data word (02 hex)
A size too big code returns if the number of words requested requires a
response block larger than 63 words. In this case, 63 words return.
An address invalid – end of section code returns when the number of
words requested extends beyond the end of this section. The data from the
specified address to the end of the section returns.
If the processor returns any other response code, no data follows.
Read I/O Word
Hex: 23
Parameters: Address of required word
Description: You must send the I/O address using the following format
(Figure A.2):
Figure A.2
I/O Address Format
0
0
0
0
0
a) Output Word
1
0
0
b) Input Word
0
Rack Number
I/O Group
Number
Rack Number
I/O Group
Number
0
12136
A-19
Appendix A
Binary Command Language
The following example command block uses the read I/O word command
to request the data and force information for the output word representing
rack 6, module group 4:
STX
02
ISC
01
SIZ
03
CMD
23
DAT
34
ETX
03
00
CHK
60
The data bytes store:
lower byte of the I/O address (34 hex)
upper byte of the I/O address (00 hex)
The processor responds to a read I/O word command with one of the
following response codes:
Response Codes
Hex
Description
00
Success
03
Forces unavailable
04
Address unknown
06
Access not allowed
08
Address not complete
When the processor returns a success response, the data buffer also
contains the data stored at the requested address, and force-on and
force-off masks associated with that data. The following example shows a
response block for a read I/O word command when forces exist:
STX
02
OSC
01
SIZ
07
RSP
00
DAT
61
1C
02
The data bytes store:
lower byte of the data word (61 hex)
upper byte of the data word (1C hex)
lower byte of the force-on mask (02 hex)
upper byte of the force-on mask (86 hex)
lower byte of the force-off mask (80 hex)
upper byte of the force-off mask (00 hex)
A-20
86
80
00
ETX
03
CHK
92
Appendix A
Binary Command Language
If no force table has been created in processor memory, the processor
responds to a read I/O word command with a forces unavailable response
code. The data stored at the specified address follows this response code in
the data buffer. The following example response block shows a read I/O
word command when no forces exist:
OSC
01
STX
02
SIZ
03
RSP
03
DAT
61
ETX
03
1C
CHK
89
The data bytes store:
lower byte of the data word (61 hex)
upper byte of the data word (1C hex)
If any other response code is returned, no data follows.
Writing Data
You can write data into processor memory either in individual words with
the write word command, or in blocks with the write block command. You
can also modify words in processor memory with the read-modify-write
command. The following two subsections explain the writing
data commands.
Write Word Command
Hex: 14
Parameters: Address that needs to be updated and the new data
Description: The following example command block writes new data into
address E3.1.5.0.0.0:
STX
02
ISC
01
SIZ
08
CMD
14
3C
05
00
DAT
00
00
08
91
ETX
03
CHK
FC
The data bytes store:
address mask (3C hex)
first address byte (05 hex)
second address byte (00 hex)
third address byte (00 hex)
fourth address byte (00 hex)
lower data byte (08 hex)
upper data byte (91 hex)
A-21
Appendix A
Binary Command Language
The processor responds to a write word command with one of the
following response codes:
Response Codes
Hex
Description
00
Success
04
Address unknown
06
Access not allowed
08
Address not complete
0F
No privilege
If any code other than success is returned, no data is written into memory.
The following response block shows a successful write word command:
STX
02
OSC
01
SIZ
01
RSP
00
ETX
03
CHK
07
Write Block Command
Hex: 20
Parameters: Starting address, number of words, and the new data
Description: The following example command block writes new data into
the first 3 words of integer file 0:
STX
02
ISC
01
SIZ
0E
CMD
20
3C
05
00
00
00
03
DAT
00
10
02
08
00
The data bytes store:
address mask (3C hex)
first to fourth address bytes (05, 00, 00, 00 hex)
lower and upper bytes of:
- size word (03, 00 hex)
- first data word (10, 02 hex)
- second data word (08, 00 hex)
- third data word (7D, 8E hex)
A-22
7D
8E
ETX
03
CHK
9D
Appendix A
Binary Command Language
The processor responds to a write block command with one of the
following response codes:
Response Codes
Hex
Description
00
Success
04
Address unknown
05
Size too big
06
Access not allowed
08
Address not complete
0F
No privilege
If the size too big response returns, the processor stores data which fits
into the existing memory locations. The rest is lost. If any code besides
success or size too big is returned, no data is written into memory. The
following response block shows a successful write block command:
OSC
01
STX
02
SIZ
01
RSP
00
ETX
03
CHK
07
The size is specified in one byte. This is true of all size specifiers within
the data buffer of a response block.
ReadModifyWrite Command
Hex: 16
Parameters: Address of the word to modify, one word AND mask, one
word OR mask
Description: The following example command block executes the
read-modify-write command:
STX
02
ISC
0D
SIZ
08
CMD
16
24
05
03
DAT
55
55
0F
0F
ETX
03
CHK
07
The data bytes store:
address mask (24 hex)
first and second address bytes (05, 03 hex)
lower and upper bytes of AND mask (55 hex)
lower and upper bytes of OR mask (0F hex)
A-23
Appendix A
Binary Command Language
When the processor receives a read-modify-write command,
it (Figure A.3):
1.
Reads the data at the specified address.
2.
Performs a logical AND operation between the data read in step 1 and
the AND mask.
3.
Performs a logical OR operation between the result of step 2 and the
OR mask.
4.
Writes the result of step 3 into the word at the specified address.
Figure A.3
ReadModifyWrite Operation
Bit Pattern
Description
1111000011110000
Initial state of specified word
0101010101010101
AND mask
0101000001010000
Result of logicalAND operation
1010000001011111
Final result
The processor responds to a read-modify-write command with one of the
following response codes:
Response Codes
Hex
Description
00
Success
04
Address unknown
06
Access not allowed
08
Address not complete
0F
No privilege
The following response block shows a successful read-modify-write
command:
STX
02
A-24
OSC
01
SIZ
01
RSP
00
ETX
03
CHK
07
Appendix A
Binary Command Language
Verify Block Command
Hex: 15
Parameters: Starting address, number of words, data to compare
with memory
Description: The processor can compare a block of data in memory to
reference data from an external device. The following command block
verifies the first three words in the binary section of the data table
(section eight):
STX
02
ISC
14
SIZ
0C
CMD
15
24
08
00
03
00
DAT
04
41
E1
02
E3
15
ETX
03
CHK
89
The data bytes store:
address mask (24 hex)
first address byte (08 hex)
second address byte (00 hex)
lower byte of size word (03 hex)
upper byte of size word (00 hex)
lower byte of the first data word (04 hex)
upper byte of the first data word (41 hex)
lower byte of the second data word (E1 hex)
upper byte of the second data word (02 hex)
lower byte of the third data word (E3 hex)
upper byte of the third data word (15 hex)
The processor responds to a verify block command with one of the
following response codes:
Response Codes
Hex
Description
00
Success
04
Address unknown
05
Address invalid - end of section
06
Access not allowed
08
Address not complete
A-25
Appendix A
Binary Command Language
If the success response code returns, the next byte contains the number of
words in the reference block which do not match the block in memory.
The following response block shows a successful verify block command:
STX
02
OSC
01
SIZ
01
RSP
00
DAT
00
ETX
03
CHK
07
The data byte stores the miscomparison count. If any other response code
returns, no data follows.
Uploading/Downloading
You can read from and write to physical locations in processor memory
using the read block physical and write block physical commands. These
commands are executed faster than read block and write block commands.
However, physical addresses change when you edit the program, which
makes it difficult to keep track of where a given word or block of data is
stored. Therefore, use the read block physical and write block physical
commands only for uploading and downloading the entire memory
contents to/from a computer.
The read block physical and write block physical commands use physical
addresses which are different than the addressing used for other BCL
commands. The address requires two words (four bytes) with the least
significant byte sent first. The most significant byte must contain the value
01 hex. The value contained in the other bytes ranges from 0 to the highest
address in the processor programmable processor (depending on the
amount of memory in the system). We explain these two commands in the
following 4 subsections.
Read Block Physical
Hex: 07
Parameters: Physical address of the first word in the block, number of
words in the block
Description: The following command block uses a read block physical
command to read 16 words starting with word 66120 (10248 hex):
STX
02
A-26
ISC
05
SIZ
07
CMD
07
DAT
48
02
01
01
10
00
ETX
03
CHK
70
Appendix A
Binary Command Language
The data bytes store:
least significant byte of the address (48 hex)
second byte of the address (02 hex)
third byte of the address (01 hex)
most significant byte of the address (01 hex)
least significant byte of the size word (10 hex)
most significant byte of the size word (00 hex)
The processor response to a read block physical command is the same as
the response to a read block command (see “Read Block Command,
page A-18).
When uploading to a computer, you need to know how much memory is
actually used. You can find the address of the last word used in memory
with the following algorithm:
1.
Read words 35 and 36.
2.
Use the least significant byte of word 35 plus word 36 as the three
least significant bytes in a physical address.
3.
Subtract 9 from the physical address in step 2.
4.
Read 2 words starting from the result of step 3.
5.
The least significant byte of the first word plus the second word read
in step 4 contain the three least significant bytes of the physical
address of the last word used in memory (Figure A.4):
Figure A.4
Finding the Address of the Last Used Memory Word
Result of step
Word 35
Word 36
Description
1
1101100000000000
0000000001101001
---------
2
0000000100000000
0000000001101001
Points to word 105
3
0000000100000000
0000000001100000
Points to word 96
4
1000001100000001
0000000001000000
Contents of words 96 and 97
5
0000000100000001
0000000001000000
Points to word 65600 (the last
unused memory word)
Although uploading does not require a complete shutdown of the
processor, memory must not be created or deleted during the upload
operation. Therefore, be sure that no scanner or other module is creating
or deleting memory, and making changes in LIST during an
upload operation.
A-27
Appendix A
Binary Command Language
Example Upload
The following sequence of command and response blocks performs an
upload. The upload includes 4DD (hex) words, and is performed in 10
(hex) word blocks. All values are shown in hexadecimal.
Device:
STX
02
ISC
SIZ
07
CMD
07
00
PLC3:
STX
02
OSC
Device:
STX
02
ISC
PLC3:
STX
02
OSC
Device:
STX
02
ISC
PLC3:
STX
02
OSC
Device:
STX
02
ISC
PLC3:
STX
02
Device:
PLC3:
DAT
SIZ
22
RSP
00
10
SIZ
07
CMD
07
10
SIZ
22
RSP
00
10
SIZ
07
CMD
07
20
SIZ
22
RSP
00
10
SIZ
07
CMD
07
C0
OSC
SIZ
22
RSP
00
0D
48
STX
02
ISC
SIZ
07
CMD
07
D0
STX
02
OSC
SIZ
24
RSP
00
10
00
00
00
ETX
03
CHK
DAT
...data...
ETX
03
CHK
DAT
ETX
03
CHK
DAT
...data...
ETX
03
CHK
DAT
ETX
03
CHK
ETX
03
CHK
ETX
03
CHK
DAT
...data...
ETX
03
CHK
DAT
ETX
03
CHK
ETX
03
CHK
00
01
00
01
00
01
10
10
10
00
00
00
DAT
...data...
DAT
04
04
00
00
01
01
DAT
...data...
10
0D
00
00
Write Block Physical
Hex: 08
Parameters: Physical address of the first location in processor memory to
receive data, number of words in the block of data, data to write into
processor memory
A-28
Appendix A
Binary Command Language
Description: The processor only recognizes the write block physical
command when in the shutdown mode. To put the processor into the
shutdown mode, use the shutdown command (06 hex). The following
example command block uses the shutdown command:
ISC
04
STX
02
SIZ
01
CMD
06
ETX
03
CHK
10
The response to a shutdown command is a success response code (00 hex).
Any other response indicates that the processor did not correctly receive
the transmission.
The following example command block uses the write block
physical command:
STX
02
ISC
05
SIZ
0B
CMD
08
DAT
01
20
01
00
02
00
19
05
20
01
ETX
03
CHK
80
The data bytes store:
least significant byte of the address (01 hex)
second byte of the address (20 hex)
third byte of the address (00 hex)
most significant byte of the address (01 hex)
least significant byte of the address (02 hex)
most significant byte of the address (00 hex)
least significant byte of first data word (20 hex)
most significant byte of second data word (01 hex)
The processor response to a write block physical command is the same as
the response to a write block command (see the section entitled write
block command).
After the download operation is complete, send a reset command (09 hex)
to exit the shutdown mode. The following command block uses the
reset command:
STX
02
ISC
06
SIZ
01
CMD
09
ETX
03
CHK
15
The processor does not issue any response to a reset command, so just
continue communication by sending the next command. However, the
reset command resets the sequence counts.
A-29
Appendix A
Binary Command Language
Example Download
The following sequence of command and response blocks performs a
download. The download includes 4DD (hex) words, and is performed in
10 (hex) word blocks. All values are shown in hexadecimal.
A-30
Device:
STX
02
ISC
SIZ
01
CMD
06
ETX
03
CHK
PLC3:
STX
02
OSC
SIZ
01
RSP
00
ETX
03
CHK
Device:
STX
02
ISC
SIZ
27
CMD
08
01
PLC3:
STX
02
OSC
SIZ
01
RSP
00
ETX
03
Device:
STX
02
ISC
SIZ
27
CMD
08
10
PLC3:
STX
02
OSC
SIZ
01
RSP
00
ETX
03
Device:
STX
02
ISC
SIZ
27
CMD
08
20
PLC3:
STX
02
OSC
SIZ
01
RSP
00
ETX
03
Device:
STX
02
ISC
SIZ
27
CMD
08
CO
PLC3:
STX
02
OSC
SIZ
01
RSP
00
ETX
03
Device:
STX
02
ISC
SIZ
27
CMD
08
D0
PLC3:
STX
02
OSC
SIZ
01
RSP
00
ETX
03
CHK
Device:
STX
02
ISC
SIZ
01
CMD
09
ETX
03
CHK
DAT
...data...
ETX
03
CHK
DAT
...data...
ETX
03
CHK
DAT
...data...
ETX
03
CHK
DAT
...data...
ETX
03
CHK
DAT
...data...
ETX
03
CHK
CHK
CHK
CHK
CHK
Appendix A
Binary Command Language
Read Section Size Command
Hex: 19
Parameters: Address of section to read
Description: The following example command block requests the size of
the data table in context 1:
STX
02
ISC
08
SIZ
04
CMD
19
DAT
03
03
ETX
03
01
CHK
31
The data bytes store:
address mask (03 hex)
first and second address bytes 903, 01 hex)
The processor responds to a read section size command with one of the
following response codes:
Response Codes
Hex
Description
00
Success
04
Address unknown
06
Access not allowed
If the processor returns a success response code, the next four bytes
contain the section size, with the least significant byte transmitted first.
The two bytes following the section size contain the number of next levels
of addressing.
For example, in context 1 of the data table, the number of next levels
corresponds to the number of data table sections such as output, input, or
integer. And in the integer section, the number of next levels corresponds
to the number of integer files.
The following example response block shows successful read section
size command:
STX
02
OSC
14
SIZ
07
RSP
00
DAT
08
28
00
00
19
00
ETX
03
CHK
69
A-31
Appendix A
Binary Command Language
The data bytes store the data word:
first size byte (08 hex)
second size byte (28 hex)
third size byte (00 hex)
fourth size byte (00 hex)
first byte of next level’s word (19 hex)
second byte of next level’s word (00 hex)
If any other response code is returned, no data follows.
Create Command
Hex: 17
Parameters: Address of the last word, structure, file or section.
Description: The following example command block creates 10 words in
integer file 5 (if integer file 6 does not already exist):
STX
02
ISC
0C
SIZ
06
CMD
17
3C
05
DAT
05
00
0A
ETX
03
CHK
7E
The data bytes store:
address mask (3C hex)
first address byte (section) (05 hex)
second address byte (file) (05 hex)
third address byte (structure) (00 hex)
fourth address byte (word) (0A hex)
If the words have already been created, the processor sends an available
response code (02 hex). The command also tells the processor to create the
pointers for integer files 0 thru 4 if they did not already exist, although no
words are allocated to these files.
A-32
Appendix A
Binary Command Language
The processor responds to a create command with one of the following
response codes:
Response Codes
Hex
Description
00
Success
01
Size too big
02
Available - address specified already exists
04
Address could not exist - invalid values
08
Address insufficient - exists, but no specific to word level
0F
No privilege
The following example response block shows a successful
create command:
STX
02
OSC
11
SIZ
01
RSP
00
ETX
03
CHK
17
Delete Command
Hex: 18
Parameters: Address of the first word, structure, file, or section to delete
Description: The delete command deletes or reduces sections in PLC-3
memory. If you specify a word, structure, or file, the processor deletes all
higher addresses at the same level.
For example, if integer file 5 contains words 0 thru 100, deleting word 10
also deletes word 11 thru 100. On the other hand, deleting the integer
section does not delete any other section.
The following example command block deletes from integer file 5 to the
end of the integer section:
STX
02
ISC
0D
SIZ
04
CMD
18
0C
DAT
05
05
ETX
03
CHK
44
The data bytes store:
address mask (0C hex)
first address byte 905 hex)
second address byte (05 hex)
A-33
Appendix A
Binary Command Language
The processor responds to a delete command with one of the following
response codes:
Response Codes
Hex
Description
00
Success
03
Unavailable - section does not exist
04
Address could not exist - invalid values
06
Access not allowed
08
Insufficient address - not specified to at least three levels
0F
No privilege
The following example response block shows a successful
delete command:
STX
02
OSC
11
SIZ
01
RSP
00
ETX
03
CHK
17
LIST Command
Hex: 29
Parameters: none required
Description: The LIST command accesses the LIST function. This
command allows you to send ASCII characters to the processor. These
characters are interpreted in the same manner as if they were entered from
the processor front panel or the keyboard of a programming device
(see chapter 3).
The processor remains in the LIST processing mode until it receives either
a command block which does not contain a LIST command or a break
character. The following example command block uses the LIST
command (with no data in the command buffer):
STX
02
A-34
ISC
31
SIZ
01
CMD
29
ETX
03
CHK
60
Appendix A
Binary Command Language
The processor responds to the LIST command with one of the following
response codes:
Response Codes
Hex
Description
00
Success
01
Size too big
Both responses are followed by ASCII data in the data buffer. The size too
big response indicates that the response contains more than 64 words. In
this case, the processor continues to send response block until the entire
response has been transmitted. All response blocks except one containing
the last block of data use the size too big response. The last block uses the
success response.
The following example response block shows a successful LIST command:
STX
02
OSC
32
SIZ
10
RSP
00
DAT
...ASCII data...
ETX
03
CHK
The first LIST command which you send should not have any data in the
command buffer. The processor response to this first command contains
the initial data which appears on the terminal CRT after you enter the LIST
command. Other LIST commands generally contain data in the
command block.
Set CPU Mode Command
Hex: 2A
Parameters: Flag byte
Description: You can change the processor operating mode with the set
CPU mode command. The flag byte allows you to change the operating
mode to program load, test, or run (Figure A.5). It also allows you to keep
other remote devices from communicating with the processor by setting the
remote lock bit.
Important: The remote lock bit is not the same as remote enable (which is
set in LIST).
A-35
Appendix A
Binary Command Language
Figure A.5
CPU Mode Flag Byte
7
6
5
4
3
2
Unused Must = 0
1
0
Bit
Mode Select
Remote
Lock
00 - Program Load
01 - Test
10 - Run
11 - No Change
0 - Remote Access Allowed
1 - Remote Access Not Allowed
12137
The following example command block resets the remote lock bit
(allowing remote access to other devices) and selects run mode:
The data byte stores the flag byte (02 hex).
The processor responds to a set CPU mode command with one of the
following response codes:
ISC
03
STX
02
SIZ
02
CMD
2A
DAT
02
ETX
03
CHK
36
Response Codes
Hex
Description
00
Success
06
Access not allowed
0F
No privilege
The following example response block shows a successful set CPU
mode command:
STX
02
A-36
OSC
11
SIZ
01
RSP
00
ETX
03
CHK
17
Appendix A
Binary Command Language
Set Operating Context Command
Hex: 2B
Parameters: New default context (any context between 1 and 15)
Description: You can change the default communication context by using
the set operating context command. If you send a value greater than 15,
the processor uses the lower 4 bits only. The processor does not accept a
default context of 0. The following example command block changes the
default context values to 2:
ISC
03
STX
02
SIZ
02
CMD
2B
DAT
02
ETX
03
CHK
37
The data byte stores the new default context.
The processor responds to a set operating context command with one of the
following response codes:
Response Codes
Hex
Description
00
Success
03
Unavailable - context = 0
06
Access not allowed
0F
No privilege
The following example response block shows a successful set operating
context command:
STX
02
OSC
11
SIZ
01
RSP
00
ETX
03
CHK
17
A-37
Appendix
B
DH/DH+ Error Codes
Introduction
This appendix describes the error codes that the scanner uses to report
DH/DH+ communication errors. Errors are of three types:
local
reply
remote
Local Error Codes
The scanner generates local errors while trying to execute one of its own
DH/DH+ message procedures. The message instruction sets the erro bit
and records the error in the message control word (see “Ladder Program,”
page 4-6). The module also stores the local error codes in the user symbol
ERROR (see “DH/DH+ Message Procedure Diagnostics,” page 7-1).
Possible local errors and their meanings are listed in Table B.A.
Reply Error Codes
The scanner generates reply errors while trying to respond to a command
message received from a remote DH or DH+ station. The scanner inserts
the reply error code in the STS or EXT STS bytes of any reply message
packet it transmits to a remote station. For reply errors, there is a direct
correlation between the error codes in the STS and EXT STS bytes of reply
messages and the error codes reported at the remote station:
If the scanner generates these codes:
STS byte
(hex)
EXT STS byte
(in hex)
00
10
30
40
50
60
70
F0
F0
F0
F0
F0
F0
F0
F0
F0
F0
F0
not used
not used
not used
not used
not used
not used
not used
1
2
3
4
5
6
7
8
9
A
B
Then the command
station stores the error
code in decimal
no error
81
83
84
85
86
87
231
232
233
234
235
236
237
238
239
240
241
B-1
Appendix B
DH/DH+ Error Codes
A value of F0 (hex) in the STS byte indicates that the EXT STS byte
actually contains the error code for the reply message.
The meaning of each error code depends on the command message that the
local station receives from a remote station. Table B.A describes the error
conditions that the various commands can generate. The error codes are
listed according to the decimal value that the command at the initiating
station stores.
When a remote station transmits a command, the local scanner might issue
a reply message that contains one of the error codes listed in Table B.A.
Error codes 81–87 appear in the STS byte of the reply message, and codes
231–241 appear in the EXT STS byte.
Remote Error Codes
The scanner receives remote error codes in a reply to a command it has
sent to a remote station. The message instruction sets the error bit and
records the error in the message control word (see “Ladder Program,” page
4-6). The module also stores the local error code in the user symbol
ERROR (see “DH/DH+ Message Procedure Diagnostics,” page 7-1).
The meaning of a particular remote error code varies depending on the
type of communication interface module at the remote station. If the
remote station is a PLC-3 controller with a scanner as the interface module,
the remote error codes have the meanings listed in Table B.A. For the
meanings of other remote error codes, refer to the appropriate user’s
manual for the communication interface module at the remote station.
B-2
Apendix B
DH/DH+ Error Codes
Table B.A
Local and Reply Error Codes
Error Code
Error Type
32
local
all
The size of the local file involved in a file assignment command is greater than
65,535 bytes.
34
local
all
A station number greater than 376 (octal) is specified for the remote address in
an assignment command.
35
local
all
Attempt to send unprotected command is invalid.
37
local
all
The perpacket timeout, set through LIST, runs out before receiving a reply. This
means that the remote station acknowledges (ACK) the command message but
does not send the reply in the allotted time (cf. error 92).
81
reply
diagnostic read
• A 2byte ADDR and 1byte SIZE field is missing after the FNC byte in the
command message.
• The number of bytes of data requested in the SIZE field is greater than the
maximum number allowed per reply packet (244), or SIZE is 0 (zero).
reply
PLC/PLC2 read
• The required 2byte ADDR and 1byte SIZE field are missing in the
command message.
• The ADDR value is odd (it does not specify a word address).
• The value SIZE is 0.
• The value SIZE is greater than 244.
• The SIZE value specifies an odd number of bytes.
reply
PLC/PLC2 bit write
Incomplete bit description because the number of bytes after the TNSW is not a
multiple of four.
reply
PLC/PLC2 word
write
• A 2byte ADDR field is expected after the TNSW word, but only one byte is
present.
• An odd number of data bytes in the command packet.
• The ADDR value is odd (it does not specify a word address).
reply
PLC3 read
•
•
•
•
reply
PLC3 bit write
More than four bytes of data exist after the address in the command message.
reply
PLC3 write
•
•
•
•
reply
PLC/PLC2/PLC3
read and write
The local scanner has executed a shutdown request to the local PLC3 controller.
83
Associated
Commands
Meaning
More than one byte of data is after the byte address.
Number of bytes to read is odd.
Number of bytes to read is zero.
Number of bytes to read is greater than the maximum allowed in a reply
packet (244).
• Sum of packet offset and size of data in words is greater than 65,535.
• Sum of packet offset and size of data in words is greater than the total
transaction size.
Less than two bytes of data are after the end of the block address.
An odd number of data bytes is after the end of the block address.
Sum of packet offset and size values specifies more than 65,535.
Sum of packet offset and size is greater than total transaction size.
B-3
Appendix B
DH/DH+ Error Codes
Error Code
Error Type
84
reply
diagnostic status
Backplane error occurred during determination of the physical address of the end
of the ladder program or of the end of user memory. In polled mode, the
RS232C port has received a NAK, which causes a system reset.
reply
PLC/PLC2 read,
write
Local PLC3 backplane error (either memory parity or timeout/disconnect). In
polled mode, the RS232C port has received a NAK, which causes a system
shutdown.
reply
PLC3 read and
write
Backplane error (memory parity or timeout/disconnect). In polled mode, the
RS232C port has received a NAK, which causes a system reset.
reply
diagnostic read
The command is an illegal request to read from the scanner's backplane window.
reply
PLC/PLC2 read
• PLC3 file does not exist.
• PLC3 file is too small.
• PLC3 file is more than 65,535 words long.
reply
PLC/PLC2 bit write
• PLC3 file does not exist.
• Destination bits do not exist in PLC3 file.
• Length of PLC3 file is greater than 65,535 words.
reply
PLC/PLC2 word
write
• Destination file does not exist in PLC3 memory.
• Destination word does not exist in the destination PLC3 file.
• Length of the destination file is greater than 65,535 words.
reply
PLC/PLC2 bit write
Keyswitch setting at local PLC3 controller prohibits access.
reply
PLC/PLC2 word
write
Local keyswitch settings prohibit writing into desired destination file.
reply
PLC3 write
Keyswitch setting disallows access to file.
87
reply
PLC/PLC2/PLC3
read and write
The local PLC3 controller is in program mode. There may or may not be a major
system fault.
91
local
all
• Handshaking lines on the RS232C link are not connected properly.
• Multiple wacks on link.
92
local
all
The remote station specified does not acknowledge (ACK) the message.
94
local
all
Remote station is disabled.
112
local
all
Undefined operator in an assignment statement or expression.
114
local
all
Illegal expression syntax.
115
local
all
Illegal unary (prefix) operator in an expression.
117
local
all
Undefined data following a valid address in a CREATE command, or undefined
data following a valid symbol in a delete command.
121
local
all
Symbol undefined because it appears as the source in an assignment command
before it is defined. For example, a statement of the form A = A + 6 generates
this error if user symbol A has not appeared previously.
123
local
all
System symbol must be a symbolic address. This error occurs if a procedure
name is used in place of a symbolic address in an assignment statement or if the
system symbol referenced in an assignment does not exist.
85
86
B-4
Associated
Commands
Meaning
Apendix B
DH/DH+ Error Codes
Error Code
Error Type
Associated
Commands
Meaning
124
local
all
Illegal destination in an assignment command or invalid data following a number
on a command line. For example, the lines 5 = 4 + 1 or 6ASDFGHJ generate
this error code. The line $rbWERTYUI generates error code 140 (unrecognized
command).
125
local
all
Illegal modifier for the CREATE command. Accepted modifiers for the create
command are LOCAL and GLOBAL.
126
local
all
The CREATE command was specified, but the symbol did not begin with an @.
127
local
all
$ missing in a CREATE system symbol address command line.
129
local
all
Attempt to delete nonexistent symbol.
140
local
all
• Unrecognized or ambiguous command.
• Channel 4 not configured for DH/DH+.
142
local
all
Illegal data following GOTO command.
143
local
all
Illegal use of label (e.g., not in a procedure).
144
local
all
Label not found.
145
local
all
Duplicate label. User symbols must be distinct from labels.
146
local
all
Too many nested procedures.
147
local
all
Insufficient privilege for the specified operation. This error can occur when an
attempt is made, via the assignment command, to write into a major section of
memory in which the scanner does not have access privileges (namely, major
section 0, 1, or 2).
148
local
all
Unbalanced parenthesis in expression.
149
local
all
A procedure name is used in a field that requires a symbolic address or a user
symbol variable.
150
local
all
A label is used in a field that requires a symbolic address or a user symbol
variable.
154
local
all
Error in reading address for symbol entry.
156
local
all
Illegal symbol in expression.
159
local
all
Bad level specified in extended address:
• More than nine levels specified in an extended address.
• Something other than a ( or a number followed a in an extended address.
160
local
all
Unrecognized section specifier. An illegal character followed the $ in an address.
161
local
all
Bad timer or counter specification:
• The first letter of the data table address is a T, C, or P, but four characters are
not in specification. Addresses that are incorrect causing this error include
$TAC:15, $C5:3, $TACCUM:23, etc.
• The key data table word specifier is four characters long and began with a T,
C, or P, but it does match the legal word specifiers (e.g., $TACM:3).
• No colon following a legal word specifier.
B-5
Appendix B
DH/DH+ Error Codes
B-6
Error Code
Error Type
Associated
Commands
Meaning
163
local
all
Missing colon between file and word.
164
local
all
Illegal word specifier in a data table address.
165
local
all
Illegal context specifier. When an expression determines the context in a data
table address, or when a data table address specifies the global context (context
0) and a colon follows the context.
166
local
all
Attempt to execute a symbol not defined as a process. The system symbol
exists but refers to a symbolic address rather than to a process. Not a DH/DH+
procedure.
169
local
all
Either the number or the expression following the \ in an address has a value
outside the range 0 to 15 (decimal).
171
local
all
Value specified in a bit assignment statement was other than a zero or a one.
177
local
all
Illegal use of EXIT command.
178
local
all
Illegal use of STOP command.
179
local
all
STOP command encountered in procedure.
188
local
all
Attempt to read/write at bad address.
189
local
all
Unable to evaluate the expression in the given base. This occurs if the argument
of a FROMBCD function is not a valid BCD bit pattern, or if invalid characters
occur in numeric values (e.g., 57 + 12X").
192
local
all
Function being used is not defined.
194
local
all
Expression is too complex.
199
local
all
Attempt to divide by zero.
200
local
all
Bad port specifier. The character following the # is other than H, h, M, m, D, d, O,
or o.
201
local
all
User symbol used as part of remote address specification.
202
local
all
Undefined data following assignment command. This error occurs if the modifier
UNRPOT is entered instead of UNPROT.
203
local
all
Error in remote specification:
• A character other than @ or $ following the station number specification
(.. . . . . . . . . . . . . . = #H045*T . . .).
• Something other than EOL, PROT, or UNPROT following a remote source
address (... = #H012$S5:8 + 9).
204
local
all
Thirdparty transfer. In an assignment command, both the source and the
destination are remote addresses.
205
local
all
Error in evaluating a PLC2 address, or PLC2 address greater than 65,535.
206
local
all
Zero range specified in an assignment command.
207
local
all
Word range specified in destination address.
208
local
all
Destination and source addresses disagree in type.
Apendix B
DH/DH+ Error Codes
Error Code
Error Type
Associated
Commands
Meaning
209
local
all
Not of DH message type.
210
local
all
Use of a nonPLC3 type address in a local address operand.
211
local
all
In an assignment command, one of the local files does not exist, or the word
specified is beyond the end of the file.
212
local
create
During CREATE command execution, the scanner was not able to create any
symbols.
213
local
all
A local file exists, but the action specified refers to addresses beyond the end of
the file. Possible causes include:
• In a word assignment statement, the offset is greater than the file size.
• In a word range assignment statement, the sum of the base address and the
offset is greater than the total file size.
• In a file assignment statement, the destination file is smaller than the source
file. If the source file is remote, a single packet is fetched from the remote
station's file.
214
local
all
Local source and destination files differ in size.
215
local
all
The value resulting from operations specified on the left side of an assignment
statement does not fit into the destination specified on the right side:
• The source is in the H section and the destination is in the N section, but the
number is too large (i.e., outside the range -32768 to +32767).
• A word is transferred from a binary section (I, O, or B section) to the N or C
section and the highorder bit is a 1.
• The destination is in the decimal section, but the number is not a valid BCD bit
pattern.
217
local
all
More than eight levels specified in file address.
218
local
all
• File size changed between packets of a multipacket transaction.
• Destination not created.
230
local
all
Reply packet too small.
231
reply
PLC3 read and
write
Error in converting the block address (major section 63, context 15, or section
15).
232
reply
PLC3 read and
write
Three or fewer addressing levels specified for a PLC3 word address.
233
reply
PLC3 read and
write
Conversion of a file address to a block address resulted in more than nine
addressing levels.
234
reply
PLC3 read and
write
Symbolic address not found.
235
reply
PLC3 read and
write
Symbolic address is of length zero or is longer than eight bytes.
B-7
Appendix B
DH/DH+ Error Codes
B-8
Error Code
Error Type
Associated
Commands
Meaning
236
reply
PLC3 read
• File not found.
• Destination address does not have enough levels to specify a PLC3 word (for
wordrange reads) or a file (for file reads).
• The PLC3 address specifies more levels than required.
• Word specified by the PLC3 address does not exist.
reply
PLC3 bit write
•
•
•
•
reply
PLC3 write
• Destination file not found.
• Destination address does not point to a word (for wordrange writes) or a file
(for file writes).
• Destination address specifies more levels than required.
• First word of destination location does not exist.
237
reply
PLC3 read and
write
• Any word in the total transaction does not exist in the destination file.
• The source and destination files are not the same size.
238
reply
PLC3 read and
write
The file size decreased between packets of a multipacket transaction and
became too small for the total transaction.
239
reply
PLC3 read and
write
File is larger than 65,535 words.
240
reply
PLC3 read and
write
Sum of total transaction size and the word level of PLC3 addressing is greater
than 65,535.
241
reply
PLC3 write
Remote station does not have access to the destination file.
243
reply
all
• No privilege for upload/download
• Words already created or already deleted.
245
reply
restart
No previous shut down command received.
255
local
all
Module being sent message does not exist. Should also get BAD ADDRESS
major system fault.
File not found.
Destination address does not specify a PLC3 word.
The PLC3 address specifies more levels than required.
Word specified by the PLC3 address does not exist.
Appendix
C
DH and DH+ Command Set
Introduction
Table C.A lists the DH and DH+ commands supported by the scanner. For
detailed information on using these commands, refer to the DH/DH+
Command Set User’s Manual (publication 1770-6.5.16).
The scanner can transmit 12 different commands on the link. The
addressing method determines which command is to be sent.
Table C.A
Basic Commands
Addressing Method
PLC2 logical data
PLC3 logical binary
or
Logical ASCII word range
Logical ASCII data type
Command
CMD (Hex)
FNC (Hex)
Protected writeblock
00
N/A
Unprotected readblock
01
N/A
Protected writebit
02
N/A
Unprotected writebit
05
N/A
Unprotected writeblock
08
N/A
Write block
0F
00
Read block
0F
01
Write bit
0F
02
Write file
0F
03
Read file
0F
04
Write block
0F
67
Read block
0F
68
C-1
Appendix
D
Specifications
Specification
Function
•
•
•
•
•
•
Location
• 1775S5 - single slot in a PLC3 chassis
• 1775SR5 - single slot in a PLC3/10 chassis
I/O Capacity per Scanner
• 2,048 I/O (any mix)
• 4,096 I/O (complementary)
Communication Rates (in kbps)
• 57.6 at 10,000 cable ft. (DH, DH+, I/O)
• 115.2 at 5,000 cable ft. (I/O only)
• 230.4 at 2,000 cable ft. (I/O only)
Cabling
• Twinaxial Cable (cat. no. 1770CD) for I/O, DH or
DH+ communication channels
• Industrial Terminal T50 Cable (cat. no. 1784CP5)
for DH+ communication to T50 industrial terminal
Nominal I/O Scan Times Per I/O
Adapter at 115.2Kbaud
•
•
•
•
•
•
Backplane Current
• 6.0A maximum from +5V
• 20mA maximum from ±15V
Environmental Conditions
• Operating Temperature: 0 to 60° C (32 to 140°F)
• Storage Temperature: 40 to 85° C (40 to 185° F)
• Relative Humidity: 5 to 95% (without condensation)
I/O communication
DH communication
DH+ communication
backup communication
peertopeer communication
frontpanel support
4.5ms for 1 channel
5ms for 2 channels
5ms for 3 channels
6.5ms for 4 channels
8ms for 3 channels + DH
9ms for 3 channels + DH+
D-1
Index
Numbers
1770-CD, 12, 115116
1771-AS, 11, 116
1771-ASB, 11, 116
1775-A1, 110, 21
1775-A2, 110
1775-A3, 110, 21
1775-CBA, 112
1775-CBB, 112
1775-GA, 62, 72
1775-KA, 72
1775-S5, 11, 111, 72
1775-SR5, 11, 72
A
accept upload/download LIST selection,
215
arithmetic operators, 610
writes LIST selection, 215
BCL, A1
commands, A16
create, A32
delete, A33
LIST, A34
read block, A18
read block physical, A26
read I/O word, A19
read section size, A31
read word, A17
read-modify-write, A23
reading data, A16
set CPU mode, A35
set operating context, A37
uploading/downloading, A26
verify block, A25
write block, A22
write block physical, A28
write word, A21
writing data, A21
extended addressing, A14, A15
protocol, A1, A13
binary command language. See BCL
bit operator, 67, 69
allocating memory, 63
bitwise operators, 610
assignment
command, 512, 613
examples, 512
formatting, 513
command line for data transfers, 48
parameters, 51
block transfers, 26, 32, 33
auto configuration, 24
B
backup
cable, 12, 112, 116, 3738
communication
channel installation, 116
operation, 3335
programming, 38
timing, 310
configuration LIST selections, 28
connector, 12
PLC3 or PLC3/10 processor, 11
switches, 110
switches location, 16
system, 11, 12
backup communications configuration, 29
C
cable lengths, 116, 23
cables for
backup, 112
DH or DH+, 114116
I/O, 116
channel timeout, 221
commands, A16
Data Highway/Data Highway+, C1
message procedure, 613
comments in message procedures, 619
communication rate, 23, 221
LIST selections, 21, 221, 222
switch, 18
comparison operators, 612
complementary I/O, 27
configuration, 21, 23, 221
backup communications, 29
DH/DH+, 210
I–2
Index
peer-to-peer, 28
CREATE command, 613, 614
reply, B1
DH/DH+ configuration, 210
DH/DH+ timeouts, 212219
D
Data Highway, command set listings, C1
data transfers, 51
duplicate I/O, 27
E
DELETE command, 613, 614
editing message instruction, 62
delimiter
label (:), 615
logical address ($), 52
logical ASCII (), 58
remote station (#), 512
remote station type (H), 512
system symbol (@), 66
error
codes for DH, B1
codes for DH+, B1
monitoring for DH/DH+, 7275
ON_ERROR command, 616, 71
user symbol, 619
DH
configuration, 43
connections, 113116
data transfers, 48412, 51514
error, B1
features, 1112
LIST selections, 22, 210220
message instruction, 61
considerations, 61
message procedure examples,
619620
Message Procedures, 6164
messages, 4647
programming, 45
status indicators, 12, 15
switch settings, 16
timing, 413
versus DH+, 412
error codes
local, B1, B3
remote, B2
reply, B1, B3
DH error codes, B1
local, B1
reply, B1
error block, operation, 73
error reporting, 71
execute command, 613, 615
EXIT command, 613, 615
expression operators, 67
expressions, 12, 67
interpreting, 68
extended addressing, A14, A15
F
field parameters, 51
abbreviations, 51
floating master, 412
FROM_BCD function, 617, 618
DH+
command set listings, C1
configuration, 43
connections, 113116
data transfers, 48412, 51514
error, B1
features, 1112
LIST selections, 210220
message procedure examples,
619622
Message Procedures, 6164
messages, 47
programming, 45
status indicators, 12
switch settings, 19, 110
timing, 413
versus DH, 412
front panel LIST selections, 220222
DH+ error codes, B1
local, B1
I/O scan
configuration LIST selection, 26
functions for message procedures,
617618
G
GOTO command, 613, 615
I
I.T. defaults LIST selection, 221
I/O communication, 31
I/O rack
in I/O chassis scanning sequence, 26
range, 220
Index
effect on program execution, 31
sequence list, 26
timing considerations, 3133
IF command, 613, 616
indicators
DH, 13, 15
DH+, 13, 15
fail, 13, 14
forces enabled, 14
I/O channel status, 13, 14
pass, 13, 14
input file for
backup communication channel, 29,
38
peer-to-peer communication channel,
28, 34
I–3
N
node
identification in LIST, 217
mode LIST selection, 211
O
ON_ERROR command, 613, 616629,
71, 75
operating mode LIST selection, 24
output file for
backup communication channel, 29,
38
peer-to-peer communication channel,
28, 34
input file list LIST selection, 216222
P
K
keyswitch position, 215
L
ladder program, 46
link, 41, 412, 414, 511
LIST function, 21
partner, 29, 38
peer-to-peer communication
installation, 116
LIST selections, 28
master, 28
operation, 3335
programming, 35
slave, 28
timing, 310312
logical ASCII addressing, 58
PLC communication on DH or DH+, 41,
5253
PLC-2, 53
PLC-5, 412
logical operators, 69
polling, 15, 25
LIST selections for scanner, 22
local error codes, B1, B3
pound sign delimiter, 510, 511
M
master number, 28
message
commands, 49
comments, 619
errors, 7275, B1
expressions, 67
for data transfers, 48
functions, 617
MSG instruction operation, 4647
procedure, 47, 621
solicited and unsolicited, 4445
symbols, 6466
Message Procedures
DH, 6164
DH+, 61
modifiers, 513
privileges, 49
procedure names, 66, 615
programming terminal, 113, 21, 72
protected commands, 49412, 514
protocol, A1
dip switch for channel four, 23
switch for channel four, 17
R
rack range, 220
reconfiguration, 222
reconfigure, 25
remote
error codes, B2
link type, 511
I–4
Index
stations, 510, 511
remote error codes, B2
system symbols, 65, 66, 614
scope, 66
reply error codes, B1, B3
resident, 29, 38
T
terminator, 16, 115
S
scanning sequence list, 26
send unprotected LIST selection, 214
shift operators, 611
slave number, 28
solicited messages, 44
specifications, D1
station
address, 211, 213
defined, 41
interface module, 41
number, 211
throughput time, 413
thumbwheel switch, 12, 16, 111
times
backup communication, 310
block transfer, 32
DH, 413
DH+, 413
I/O scan, 32, 413
peer-to-peer communication, 310
token passing, 412
TO_BCD function, 617, 618
trunkline, 41
twinaxial cable, 12, 114116
stop bits LIST selection, 221
STOP command, 613, 617
switch settings
backup system, 110
communication rate for channel four, 18
protocol for channel four, 18
station number for DH/DH+ station, 19
terminator, 16
symbolic addresses, 66, 614
symbols, 6466
reserved words, 65
U
unprotected commands, 410412, 514
unsolicited messages, 44
user symbols, 65, 66
using this manual, P 1P 3
audience, P 2
contents, P 1
related publications, P 2
vocabulary, P 2
PLC, PLC-2, PLC-3, and PLC-3/10 are registered trademarks of Allen-Bradley Company, Inc.
PLC-5 and Data Highway Plus are trademarks of Allen-Bradley Company, Inc.
With offices in major cities worldwide
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Publication 1775-6.5.5 –– November 1992
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PN 955113-06
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Copyright 1991 Allen-Bradley Company, Inc. Printed in USA